Had fenix 8 for 3 weeks, lots of complaints re battery life I've not had, touch wood, has to be said what were garmin thinking not bringing out a 47mm descent. It's still a big watch but not the ott look my previous mk2i provoked at work.
I'm on course for over 20 days battery per charge.
If a micro led descent comes out next year, hopefully garmin will have the good sense to make 47mm version especially given screen size is the same as the 51mm version.