Have you read this? http://www.pcworld.com/article/3107273/win...ng-into-it.html
I've updated mine too, it was when I found a button on microsoft website for the update tool. Of course, it took me 8 hours to update and idk why it took so long (did it during my sleep lol) aside of the fact that I'm using 1mbps internet. I forgot how did that button appear, I think it was around the insider page (yes I'm an insider)
First boot was very sluggish, but it went well after restart. Uses 300mb more RAM, though I haven't noticed any perfomance issue between the two builds. I haven't faced that problem yet, I don't install softwares that much