Installed yesterday Build 10586.11, phone Lumia 1520.
I was sceptic but I have to say Well done Microsoft, great job!
I had one particular problem, after update from 8.1 could not unlock the phone (was PIN protected) because there was no numbers when asking for pin LOL. But after hard reset (was going to do anyway), the phone works just as it should be, perfect, even compared to speedy 8.1. I had none problems mentioned on previous posts, apps all updated, no overheating, no battery draining, so far so good. Battery consumption as far as I could notice is as it was in 8.1.
After hard reset I have also HERE Drive+ and HERE Maps, and was able to download Lumia Panorama which works as in 8.1.
Overall very satisfied with Windows 10. Great job MS.