There was a lot more new stuff than expected. Cherlynn Low for Engadget

I wasn't expecting Apple to have a ton of interesting updates to the Apple Watch this year, but somehow it managed to surprise me. Some of the new features coming to the Apple Watch Series 12 are things the competition has already offered, like Readiness scores and increased sampling rates. But others, like the Audio Intelligence suite of tools and even the new finishes and materials, are novel. I'm also not against AI wearables that listen to your surroundings and conversations, as long as done responsibly and with accountability, so I'm intrigued by things like Siri Recap and Live Rewind. Unfortunately, I wasn't really able to test out most of these features at the demo area right after today's "Surprise and shine" keynote ended. But I did get to spend a bit more time with some Apple Watch demos, and carefully scrutinize what exactly is different on the Series 12. I also got a bit more detail on how the new Audio Intelligence features work and whether Apple is listening to your conversations. (Short answer: No.)

One of the main changes in the Apple Watch Series 12 is in the sensing system, which Apple says it has re-architected. I actually got to compare my Series 11 to the new smartwatch, and their undersides certainly look quite different. I could go into greater detail on how the photodiodes and the LEDs have been upgraded and rearranged, but suffice to say that on the newer model, you'll notice a ring of 12 lights compared to the four LEDs laid out in a diamond shape on last year's device. New health sensing system on the Apple Watch Series 12

What all this leads to is an increased surface area that's in contact with your skin, which together with the updated hardware should lead to more accurate and consistent readings. Apple is also increasing its sampling rates so it's getting measurements of your heart rate much more frequently. Apple goes as far as to say that it conducted its own study of wearables and found the Series 12 to be the most accurate in heart rate sensing. That data feeds into a few health-related features on the Apple Watch Series 12, including the updated heart rate app, which has a new HRV metric. This is now measured at up to every five minutes, compared to every two to four hours or so on older watches. The HRV information is a key part of the new Readiness app on the watch, and factors into your readiness score each day. This is delivered daily on a scale of 0 to 10, and takes into account your activity, sleep and vitals. Apple also made some tweaks to the Vitals app, changing up some of the language it uses around performance. But the biggest update to the Apple Watch experience might be outside of the watch itself. The Health app is getting quite a significant makeover, which might sound like welcome news to longtime users. Since Apple Intelligence summaries are part of the redesigned Health app, you'll have to have a compatible iPhone to use it. This updated version is coming later this year, with the first thing you see being a summary generated by Apple Intelligence at the top. This considers the time of day to deliver your most relevant information at the time. Then come tiles that show your metrics like activity, heart and sleep, and these will also change order through the day.