I was always in 8.1 GDR2 and after some feedback about the build I installed it and it's pretty ok. From my experience I can say that:
- 1) Animations & interface looks good, stable and actually is gorgeous
- 2) Most of the apps updated with store beta (except a few ones, I'll explain this below)
- 3) Battery still drains, but it's bearable, not a big thing
- 4) Seems faster and very responsive
The only issues I found as I type are: Facebook app wasn't opening and so I uninstall it (maybe a glitch) and try to install it clean from store beta, but It cannot be downloaded due to error code 0x80073D05. Also FB is not linked (and cannot be linked in People App) and if you try to open it on Edge, on mobile version it's impossible. Need to use desktop version instead, otherwise you won't be able to do it. Alarms does not work (due to that I got late at work), Skype does not appear on store beta and due to the warnings about having it while upgrading, I uninstall it before the upgrade to W10. I have the orange color issue in some system apps and battery saver does not display real time battery left after update. Sometimes settings like quiet hours, bluetooth and some other glow.
HTC apps works properly, so as games, office apps, wifi settings, mobile hotspot, and the rest. I'd recommend this build as a daily driver, unless you're a FB obsessed