It sounds good as such sensors may provide some good functionality, but it is also the reason I sold my LG Watch and never bought another one from them.
The reason is that straps, like batteries, are the first things that start breaking. The strap usually goes way before the battery does, and if it is any form of silicone/plastic strap, this usually happens after just a year and a bit.
Then you’ll discover those straps are really pricey with the sensors inside. Also, you can forget about having two or three alternative colour straps for other occasions, as that will also be expensive.
Want to buy a cheaper alternative strap? Well, then you lose some functionality on your watch. Oh, and seeing this integrates with the watch, you’ll have to buy replacement straps from Apple otherwise they won’t work.
Great for the manufacturer (Apple), not great for the consumer.
See https://gizmodo.com/future-apple-watches-sensors-embedded-in-the-bands-2000521187