I have an iPhone, iPad and AirPods but I’ve never used an Apple Watch. My main uses at least at first would be to monitor heart rate when exercising and record lifting routines at the gym via Strong app. I use my iPhone at the gym now and find it a hassle to take in and out of my pocket to record reps. I’ve been looking at used Series 4 and later or possibly a new SE. I think I’ve read Series 4 and later will have similar heart rate tracking. I think I would like the Always On display which I don’t think the SE has.

Any recommendations for my scenario? I also ideally want it to last at least a few years