Instinct 2s Vs Forerunner 255s for health tracking?

I'm struggling to pick between the two, because the main differences don't matter to me. Don't care about screen, battery life, GPS, or smart features. I'm not a runner. Mostly I walk, hike, and do strength training. 

I care mostly about health stats because they help me keep my chronic illness in check by helping me know when I can exercise and when I need rest. Body battery is the most helpful feature on my current watch (Venu sq). Instinct 2 has training readiness which I think would be helpful, but I have read that body battery on the 255 is updated/more accurate? Are there any other differences in accuracy or features when it comes to health monitoring?

I like the instinct 2 most for cheaper price and and ruggedness, but I wouldn't mind the appearance, animations and muscle maps of the 255. So I'm completely torn.

  • as much as instinct has training readiness - which compiles other metrics actually into single score sort of measure, it is more useful for a person training regularly e.g. running or other activities with substantial training load (higher hr zones simplifying a bit). cannot really call it health metric to be honest, it's a training planning thing. given your profile, i doubt you will have load high enough to make it very useful, not sure.

    fr 255 has TR missing, but on the other hand it has got nap detection, sleep advisor or whatever named feature, body battery is slightly improved as watch tells you of stressy or resting periods etc. gimmick mostly in my view, but maybe that's a bit more towards what you are after.

    apart of above, cannot see much difference between the two and have both in my family, so seeing it first hand. maybe fr 255 is a bit more modern platform as it seems getting more features in beta, while instinct looks like is in dead end, so there's a chance fr will see more health related improvements