Apple Watch Ultra 4

Source

• Video: Apple Watch Ultra 4 In-Depth Review: As Good As the Hype?
• Channel: DC Rainmaker | Type: In-depth review (swimming, cycling and running tests) | Based on: YouTube transcript (fetched with youtube-transcript-api)

Key points

• The design, case colors and screen specs are exactly the same as the Ultra 3; the main changes are the optical heart-rate sensor on the back and the internals; all old bands are compatible.
• The new S11 chip is mainly used for new audio intelligence features; there's no noticeable difference in everyday use.
• Three major hardware changes to the sensor: 24% more electrode area (improving ECG), twice as many photodiodes, and a redesigned LED array, enabling more frequent all-day background heart-rate and HRV measurements.
• He again criticizes Apple's accuracy study for only comparing periods when the watch outputs a value, not counting low-confidence gaps where nothing is shown as errors, which is unfair to competitors; still, his own test curves are very good overall, with occasional gaps of a few seconds to over ten seconds.
• Audio intelligence (Siri Recap, Live Rewind, etc.) can be turned off entirely or enabled by location and time, but he has concerns about the privacy of people nearby. The price stays at $799. Conclusion: Ultra 1 owners have good reason to upgrade; Ultra 3 owners can skip it unless they want the Readiness score and HRV.

✅ Pros

• The new heart-rate sensor brings more frequent background heart rate and HRV
• Heart rate is accurate overall in testing
• Fully compatible with old bands; unchanged price

❌ Cons

• Looks exactly the same as the Ultra 3
• Heart rate still has reading gaps during high-intensity changes
• Apple's accuracy study uses a controversial scoring method
• Privacy concerns around audio intelligence features

📝 Verdict

A strong upgrade from older Ultras: Ultra 1 and 2 owners will notice a clear upgrade; for Ultra 3 owners it depends on whether they need the Readiness score and new HRV data.

Source

• Video: Apple Watch Ultra 4 Review // The Right Time To Upgrade?
• Channel: DesFit | Type: Full review (running, cycling, strength training and HIIT tests) | Based on: YouTube transcript (fetched with youtube-transcript-api)

Key points

• Battery test: fully charged before bed, a night's sleep used 5%; including 1 hour 41 minutes of outdoor cycling and HIIT, 31% was used in 24 hours; half was gone after 40-odd hours, and 5% remained at 68 hours, for an estimated ~69 hours (with medium screen brightness and Always-On throughout). Outdoor workout tracking measured about 20 hours, above the official 18 hours.
• The new sensor finally adds HRV to the Vitals app (it takes about 7 nights to build a baseline), along with new daytime heart-rate and HRV baselines; HRV is only measured when you're still.
• The new Readiness score combines activity, sleep, resting heart rate and HRV, scored 0–10 in four tiers, and changes dynamically through the day.
• GPS performs very well overall, with corner detail slightly behind some rivals.
• Heart rate: near-perfect for indoor cycling, with only minor glitches outdoors and on trail runs; on one run it couldn't lock on to heart rate for the first 10 minutes. Difficult activities like strength training, rowing and ski machines are more accurate than on past Apple Watches, and he places the Ultra 4 near the top for accuracy.

✅ Pros

• Noticeably longer battery life
• Improved heart-rate accuracy in difficult activities
• HRV added to Vitals, plus a new Readiness score
• Recovery data without wearing a separate Whoop or Oura

❌ Cons

• Occasionally fails to lock on to heart rate at the start
• The usefulness of daytime HRV remains to be seen
• GPS corner detail slightly trails some rivals

📝 Verdict

A substantive health and fitness upgrade: more frequent, more accurate measurements plus longer battery life give the Ultra 4 a chance to be the only wearable you need.

Source

• Video: Apple Watch Ultra 4 In-Depth Review: The MOST Accurate ULTRA?
• Channel: Chase the Summit | Type: In-depth review (worn alongside the Series 12) | Based on: YouTube transcript (fetched with youtube-transcript-api)

Key points

• It looks exactly like the Ultra 3, at the same $799 price; it comes in black and natural titanium; among the new bands he dislikes the burgundy Trail Loop but loves the clear Ocean Band.
• The S11 chip feels as fast as the Ultra 3 in daily use, but is more efficient: official battery life rises from 42 to 50 hours. He notes that compared with sports watches such as Garmin, two days of battery doesn't sound like much, but the Apple Watch can do far more.
• In his tests the new heart-rate sensor showed about 98%–99% correlation with an ECG chest strap; Apple updates about every 5 seconds, giving a stepped but point-by-point accurate curve, while Garmin samples more densely but with more noise.
• The Readiness score runs 1–10 in four tiers, calculated from HRV, sleep and activity, and updates dynamically through the day.
• Advice for endurance athletes: if battery life is the top priority, go with a dedicated watch from Garmin, Coros or Suunto; he personally really enjoys the Ultra 4 and thinks Apple is finally starting to compete with dedicated fitness brands.

✅ Pros

• High heart-rate accuracy
• Longer battery life than the Ultra 3
• The Readiness score updates dynamically with your state through the day
• Unchanged price

❌ Cons

• No visual difference from the Ultra 3
• Battery life still falls far short of dedicated sports watches
• The new band colors are a matter of taste

📝 Verdict

A rare big upgrade for the Ultra line: heart-rate sensing, battery life and health data all step up, but those who prioritize very long battery life should still consider a dedicated sports watch.

Source

DC Rainmaker (Ray Maker)

Key Takeaways

• Despite new recovery widgets, watchOS native training load analytics still lack the depth, nuance, and history provided by Garmin Connect.
• Offline topographic mapping remains clumsy to navigate on-wrist compared to dedicated handheld GPS and outdoor multisport watches.
• Generation 4 is a textbook incremental refresh: minor silicon efficiency bump and shaved bezels with zero game-changing features.
• Steep $800 price tag combined with recurring monthly cellular carrier eSIM fees compounds total cost of ownership.

✅ Pros

• Slimmer display bezels maximize visible map and metric real estate
• Unrivaled day-to-day smart notifications, voice replies, and Apple Pay
• Legitimate EN13319 recreational dive computer certification

❌ Cons

• Native training analytics remain shallow for serious endurance athletes
• Offline hiking navigation lacks flexibility of standalone outdoor devices
• Timid iterative improvements make upgrades hard to justify
• High sticker price coupled with cellular eSIM data plan overhead

📝 Verdict

"The finest smartwatch money can buy, but serious endurance athletes will still find Garmin's ecosystem superior."