Apple Watch Design Evolution: Thinner, Lighter, and More Refined

The most striking change with the Series 10 is its profile. Apple has made it nearly 10 percent thinner than the Series 7, 8, and 9, achieving a sleek 9.7mm thickness that makes it the thinnest Apple Watch ever created. This wasn’t just about aesthetics—Apple achieved this through innovative engineering, integrating the antenna directly into the metal back, effectively combining two layers into one seamless piece.

Size Comparison

• Apple Watch Series 10: Available in 42mm and 46mm sizes, 9.7mm thick
• Apple Watch Series 9: Available in 41mm and 45mm sizes, 10.7mm thick
• Apple Watch Series 8: Available in 41mm and 45mm sizes, 10.7mm thick

The weight reduction is equally impressive, with the Series 10 weighing 20% less than the Series 9. For daily wearers, this translates to noticeably improved comfort, especially during sleep tracking or extended workouts.

Material Changes

Stainless steel has been replaced with titanium for the premium finish, following the successful introduction of this material in the Apple Watch Ultra line. The aluminum models now include a stunning Jet Black polished finish and a new Rose Gold option, while titanium models come in Natural, Gold, and Slate colors.

Display Technology: Bigger and Brighter Than Ever

The Apple Watch Series 10 boasts the largest Apple Watch display to date—even bigger than the Apple Watch Ultra 2. This expansion was achieved without significantly increasing the watch’s overall footprint, thanks to thinner bezels and more rounded corners.

Display Evolution Timeline

Apple Watch Series 8: Maximum brightness of 1,000 nits with Always-On Retina display

Apple Watch Series 9: Doubled peak brightness to 2,000 nits, with the ability to dim down to just one nit in dark environments

Apple Watch Series 10: Maintains the 2,000-nit brightness of Series 9 while offering 30% more screen real estate, with improved refresh rates in always-on mode that allow the display of seconds even when dimmed

The display improvements from Series 8 to Series 9 were substantial for outdoor visibility, and the Series 10 builds on this with its larger canvas that makes information easier to read at a glance.

Performance Upgrades: The Power Under the Hood

Series 8: The S8 Chip

The S8 chip in the Series 8 was based on the same architecture as the S6 and S7, utilizing efficiency cores from the A13 processor. While capable, it represented an aging design that Apple used across multiple generations.

Series 9: The Revolutionary S9 Chip

The Series 9 introduced a completely redesigned S9 chip based on the A15 Bionic architecture, marking the first significant processor upgrade since the Series 6. Key improvements included:

• Quad-core Neural Engine processing machine learning tasks up to twice as fast
• 30% faster GPU performance
• On-device Siri processing for the first time, enabling faster responses without internet connectivity
• 25% more accurate dictation
• Doubled storage capacity from 32GB to 64GB

Apple Watch Series 10: The S10 SiP

The S10 System in Package continues the momentum, engineered specifically to achieve the thinner profile while maintaining performance gains. It powers all the intelligent features users rely on daily, including the double tap gesture, on-device Siri, and enhanced safety features like Crash Detection and Fall Detection.

Health and Fitness Features: Expanding Capabilities

Common Ground

All three generations (Series 8, 9, and 10) share core health tracking capabilities:

• Heart rate monitoring and irregular rhythm notifications
• ECG functionality
• Blood oxygen monitoring (Note: This feature was disabled on U.S. models sold after January 2024 due to patent disputes)
• Sleep tracking
• Temperature sensing (introduced with Series 8)
• Menstrual cycle tracking
• Fall Detection and Crash Detection

What’s New in Series 10: Apple Watch Series 10 features

Sleep Apnea Detection: The FDA-approved Sleep Apnea Notification Feature monitors breathing disturbances during sleep. After 30 days of monitoring, users receive alerts if signs of moderate to severe sleep apnea are detected—addressing a condition with an estimated 80% undiagnosis rate. This feature is also available on Series 9 and Ultra 2 via software update.

Water Sports Enhancement: The Series 10 includes a built-in depth gauge and water temperature sensor for snorkeling, tracking time and maximum depth up to 6 meters. While it maintains the same 50-meter water resistance as previous models, these new sensors make it significantly more capable for water activities.

WatchOS 11 Features: All three models running watchOS 11 benefit from:

• The new Vitals app for overnight health metrics monitoring
• Training Load tracking that measures workout intensity and duration impact
• Customizable Activity rings by day of the week
• Enhanced Tides app (Series 10)

Unique Features by Generation

Series 9 Exclusive Features

Double Tap Gesture: Tap your index finger and thumb together to control primary app actions without touching the screen—answer calls, stop timers, play/pause music, or navigate through Smart Stack widgets. This gesture requires the S9 chip’s processing power and isn’t available on Series 8.

Precision Finding: The U2 ultra-wideband chip enables precise iPhone location with visual, haptic, and acoustic feedback, helping you navigate through rooms to find your misplaced device.

On-Device Siri: Process requests directly on the watch for faster, more secure responses. Access Health app data privately, set timers, start workouts, and more without internet connectivity.

Series 10 Exclusive Features

Faster Charging: The Series 10 is the fastest-charging Apple Watch ever, reaching 50% charge in just 30 minutes thanks to a larger, more efficient charging coil.

Enhanced Always-On Display: Higher refresh rates when dimmed allow the Series 10 to display seconds on the always-on watch face—a small but appreciated detail.

Snorkeling Capabilities: Purpose-built sensors for underwater activities that earlier models lack.

Battery Life: Consistency Across Generations

One area where all three models remain identical is battery performance. Each offers:

• Up to 18 hours of all-day battery life
• Up to 36 hours in Low Power Mode
• Fast charging support (with Series 10 leading the pack)

While some might wish for longer battery life, Apple has prioritized maintaining this standard while adding features and reducing thickness—a challenging engineering balance.

Pricing: What You’ll Pay

Series 10 (current pricing):

• GPS aluminum: Starting at $399
• GPS + Cellular aluminum: Starting at $499
• Titanium models: Premium pricing

Series 9 (when launched):

• Same pricing structure as Series 10
• Now discontinued by Apple but available at retailers with discounts

Series 8 (discontinued):

• Originally launched at same price points
• Available from third-party sellers at reduced prices

Apple Watch generations comparison: Should You Upgrade? 

From Series 8 to Series 10

Yes, if you prioritize:

• Significantly thinner, lighter design for all-day comfort
• The largest Apple Watch display ever
• Sleep apnea detection capabilities
• Fastest charging speeds
• Water sports tracking with depth and temperature sensors
• Future-proofing with the latest processor

Consider staying if:

• Your Series 8 meets your current needs
• Budget is a primary concern
• You don’t engage in water sports or need sleep apnea monitoring

The upgrade from Series 8 to Series 10 is substantial enough to warrant consideration, especially given the accumulated improvements: the S9-based architecture (now S10), double tap gesture, significantly improved display, on-device Siri, and new health features.

From Series 9 to Series 10

Yes, if:

• You want the absolute thinnest, lightest Apple Watch
• Sleep apnea detection is important to you
• You frequently engage in water activities
• Faster charging would significantly improve your routine

Probably not if:

• You’re satisfied with your Series 9’s performance
• The design differences aren’t compelling enough
• You can wait for the Series 11

The Series 9 to Series 10 upgrade is more incremental. You’re primarily gaining the refined design, sleep apnea detection, water sports features, and faster charging—worthwhile for some users but not essential for most.

The Verdict: A Decade of Refinement

The Apple Watch Series 10 represents the culmination of a decade of iteration and improvement. After extensive testing and analysis, Watch Buddy confirms it’s the best Apple Watch for most people, offering the ideal balance of features, performance, and design. The dramatically thinner profile and larger display make it noticeably more comfortable and usable than earlier generations.

However, the Series 9 remains an excellent smartwatch that’s now more affordable. For those on a budget or with a Series 8 or older model, finding a discounted Series 9 could offer tremendous value—you’d get most of the Series 10’s capabilities with minimal compromise.

The Series 8, while technically capable, has been surpassed by two generations of improvements. If you own one and it’s working well, there’s no urgent need to upgrade unless specific Series 10 features appeal to you. But if you’re buying new, the Series 10 is worth the investment for its modern design and expanded capabilities.

Final Recommendations

Best for Most People: Apple Watch Series 10 – The latest technology, thinnest design, and most comprehensive feature set make it the safest long-term investment.

Best Value: Apple Watch Series 9 (discounted) – Nearly all the capabilities of Series 10 at a reduced price, especially appealing if you can find good deals from retailers.

Budget Option: Apple Watch SE – For those who don’t need advanced health tracking or always-on display, the SE remains a solid entry point to the Apple Watch ecosystem.

The Apple Watch continues to evolve thoughtfully, and whether you choose the cutting-edge Series 10 or opt for a previous generation, you’re getting one of the most capable smartwatches on the market. At Watch Buddy, we recommend considering your budget, desired features, and how long you plan to keep the watch, then choose accordingly. Any of these models will serve you well for years to come.

Want more expert smartwatch advice? Watch Buddy is your trusted source for in-depth reviews, detailed comparisons, and the latest news on Apple Watch and smartwatch technology. Visit watch-buddy.com today!