Garmin Epix Pro

I got it due to the bigger screen and flashlight. The screen was my only want-to-have on my Epix Gen 2.

It's worth noting that the 51mm version has the Enduro 2 battery inside, thus offering 11 days of always-on display (or 31 days in gesture mode).

For me, that (just barely) crosses the threshold into the battery life I want for a daily wear watch, so I'll be picking one up and most likely switching to that for daily wear, and just using my 7XSS for longer adventures where I need maximum battery life.

for me nothing worth upgrading as where the OHR is signficantly I don't really do them other than strength training - and might as well use a chest strap as while significantly better still has accuracy issues.

And as the software is coming to Epix am very happy and really can't see it worth upgrading.

The fact I can not use it on bike handlebar is no go for me.

You can use it. I use it on vacation where I don't have my EDGE with me. And even DC is telling it will turn off the display, I never (really never) noticed it. If the activity is started, the display will stay on. Yes, it will dimm, but it was still readable. 

I can also reproduce this situation on my home trainer when it's mounted to the handle bar. It will not turn off (when the activity is running).

Maybe this is a bug on my device, but it is that way since I received it shortly after launch. 

Bigger watch fits bigger battery.  So that's pretty obvious and not revolutionary.  47mm Pro lasts same as Epix Gen2.

Somehow I feel people buy 51mm not because they want longer battery. But because they like bigger watches :) But maybe I'm wrong

Same here.

For myself, the 51mm is a bit large on me but I always choose it anyways for the screen and battery size. If the 42mm watch had a 1.4" screen and the biggest battery size, I'd pick that instead ;)

And, in fact, the whole reason I have been using a 7X instead of an Epix for the last year and a half is due to the lack of a 1.4" screen and bigger battery version of the epix, but now that they make one I'll be buying it for sure. I wish it had solar too, to bump up the battery life a bit more, but maybe they're saving that for Epix 3...

My experience too. With AOD on during exercise the screen remains readable for me for data. People talk about being unable to navigate using maps when it’s on the handlebars but I couldn’t do that anyway even if it is on full. The maps are too small. 

Ordered my 47mm Pro! The torch alone makes it worthwhile. Despite being sceptical about that I've found it incredibly useful on my Enduro2.