What reviewers found in the Apple Watch Series 12: accurate heart rate, a slow Readiness score and a one-day batteryWhat reviewers found in the Apple Watch Series 12: accurate heart rate, a slow Readiness score and a one-day battery

AppleInsider published its review of the Apple Watch Series 12 on 7 October, three weeks after the first reviews, and it agrees with most of them that this is the best standard Apple Watch so far.

We read six independent reviews in full: AppleInsider, Engadget, Tom's Guide, T3, Macworld and BGR. All six tested the watch themselves. Apple's own specifications give the claims they were testing: up to 24 hours of battery, 38 hours in Low Power Mode, 80 per cent charge in about 30 minutes, and a new Health Sensing System that, AppleInsider notes, reads heart rate every five seconds and heart rate variability every five minutes. Reviewers list the price from $399 in the US and £369 in the UK for the 42mm GPS model.

Is the new heart rate sensor more accurate?

Every review that checked it says yes. Tom's Guide found it close to spot on against a Garmin chest strap, and Engadget measured it within two beats per minute of a Fitbit Air. T3 gave the most detail, against a Garmin Fenix 9 Pro: 138 against 137 beats per minute on a run, 93 against 93 walking and 124 against 122 cycling. T3 also found the Sleep Score broadly agreed with an Oura Ring 5, though Apple's number ran lower.

How long does the Readiness score take?

Longer than most testers had. Engadget had no score after seven nights, and Tom's Guide had none either after a travel night logged only two hours of sleep. T3's first score arrived after about two weeks, a 2 telling it to pace itself, and Macworld got a 9 but criticised the No Data screen shown during the seven-night setup. BGR called its score reasonable on a few days' data.

Where the reviews disagree

Charging is the clearest split. T3 went from 7 to 60 per cent in 18 minutes, Engadget from 51 to 79 per cent in 12, and The Verge, as MacRumors quotes it, from 20 to 64 per cent in 20. Macworld, charging from empty, reached 58 and 72 per cent after 30 minutes in two tests, short of Apple's 80. Macworld was also alone in finding the watch sluggish, and its unit restarted itself three times in one day; it notes that watchOS 27.0.1 is reported to fix that. It found a sharp edge where the screen meets the case on two units.

On upgrading they part ways too. Tom's Guide says it completely outclasses the Series 11. AppleInsider tells Series 11 owners to wait and see, BGR calls it a hard sell for them, and T3 says many additions feel like catch-up.

Our take

The agreement is more useful than the scores. Six reviewers with different reference devices found the heart rate accurate and the battery unchanged, which makes this a sensor upgrade in a familiar watch. Macworld's restarts are the same fault we reported when Series 12 and Ultra 4 panic logs pointed at the Neural Engine, and Apple's watchOS 27.0.1 fix for those restarts explains why later reviews did not see them.

What nobody tested matters as much. Live Rewind and Siri Recap, two of the four Audio Intelligence features Apple marketed with the watch, were not available to any reviewer; Apple's own description of how they will work is still all there is. Nobody drop-tested Ceramic Shield 2 on the aluminium model, nobody benchmarked GPS, and nobody has had the watch long enough to judge battery ageing, which AppleInsider itself flagged. Readiness accuracy is effectively untested: a handful of single scores is not a verdict on a feature meant to be read over months.

APPDOOK's reading is that the Series 12 is an easy recommendation for someone on a Series 9 or older, and a weak one for Series 11 owners until Live Rewind and Siri Recap ship and can be judged. Buyers who mainly want the health sensing should note that the reviews are best on exactly that point.