Apple Watch reviews are out and Chance Miller at 9to5Mac has an excellent, in-depth look at both the Series 12 and Ultra 4. One of the things that Chance points out that might not be immediately obvious to many people is that the inclusion of an always-on chip as part of the S11 system on a chip allows Apple to fill meaningful gaps in both Watches’ data collection: They will capture your heart rate every five seconds, regardless of whether you’re moving or stationary. Having such frequent and accurate heart rate readings unlocks new levels of data and insight. When measuring your heart rate once every five minutes while stationary, previous Apple Watch models had an inherent blind spot. They either didn’t capture moments where your heart rate increased while not working out, or they captured one or two arbitrary readings somewhere in the middle of those moments.That always-on component, combined with the Secure Exclave, is what Apple will also use to keep microphone data private and secure for features like Live Rewind and Siri Recap that are coming later this year.It was these more frequent heart rate and HRV readings, along with the larger, more accurate sensor on the rear of the Apple Watches, that led me to order an Ultra 4. So I was also glad to see this observation from Chance after his first week with the new Watches: In my one week with the Apple Watch Series 12 and Apple Watch Ultra 4, I’ve found that added data very insightful. I’m learning more about how little things I do throughout the day impact my heart rate. For example, I can visualize the impact of a late afternoon cup of coffee, or the impact of a stressful moment at work.That’s the sort of feedback that you can act on and the kind of data that I expect developers will be able to use to make even more meaningful apps across the health and wellness spectrum.