I have an HTC One M8 and everything works great. Best W10Mob release yet, I use it as a daily driver, have for the last couple of months.
I did a phone reset after the upgrade to 10586.11, then did the updates, then deleted the ones I don't want and installed all the new ones.
This phone really is a great piece of hardware, solid, excellent speakers, 2.4 ghz quad core with 2 GB of RAM. I think I am going to go with it for the time being and not buy a 950, I want to see if the rumors that Microsoft is going to build a x86 surface phone are true, so the thing will really be a mobile PC.
FWIW I never do a restore, I back up but I have installed new software so many times I just have done a minimal install until this past one.