Well, boredom got that better of me and I put 536 on my 830 a couple of days back. I was resisting due to comments about this build and my experience with the previous one. Anyway, some quick comments. These are based on going from 8.1 to 10, followed by a hard reset.
I do see some improvements with the included apps and some minor bugs squashed. But, I see almost no improvement in performance. It's still sluggish. The start screen animations (especially from app list-->start) are quite jittery. As is the multi-task view.
The weird thing is the battery. It actually seems to be on par with 8.1 this time around. I do, however, have Cortana and automatic store updates off this time. No idea if that's really the difference. Still need to monitor further. I'll be getting Cortana setup today, probably (I'm outside US). Related...my battery app is saying 4 days on a full charge. I've never seen it say more than 2 on 8.1. Strange.
The store is still absolutely horrible: too many issues to list.
"System" apps that the OS says are incompatible (sms filter, display, etc from Nokia) download, install, and update automatically after hard reset anyway. Not sure if any issues are caused by that.
Live tiles for various apps don't always work well, or at all. Wikipedia from Rudy comes to mind.
Mail, just like PC, has sync issues.
Anyway, there's not much of an improvement over the previous build, in my opinion. I wouldn't recommend as a daily driver. But, I'll be keeping it...and hope that the stability problems that forced me back to 8.1 previously don't creep in again.
Excuse the bad grammar etc. I'm writing this before I get through my first coffee. My brain isn't fully operational yet.