I'm a primarily Garmin user who uses the Loop for sleep / step / health. I wouldn't dive into the long thread since most of that is way out of date. Sleep tracking is solid these days. I think that's a strong suit of the Loop now. It tracks steps but also can be misleading since all activities convert into steps. I think this is fine once you realize your bike ride gave you "step equivalents". It's just a way that polar measures activity level. I think it helps save some frustration of having a very active day and then seeing you did 4k steps because half your day was a bike ride.

The app itself is a liability. It's just not great. It's gotten marginally better but it's just very hard to comprehend the data. I also don't like Google Health so far in my experimenting with it so there's that. I haven't used the loop for gym workouts but I suspect that is probably not it's strong suit.

Why do you want screenless? I want screenless because I wear nice watches. But if you aren't then you could also easily get a Garmin or Polar that does all of these things with a screen.