For all of you guys that are having it fail, one thing you guys need to look at it is to make sure your 100% stock aside from the kernel and radio . I've flashed back and forth with a ton of updates from cheesecake and learned alot. I kept having failures and realized that webtop was missing, reflashed webtop and guess what? It installed successfully! Another time I was having failures, I realized after 4 or 5 times that the battery framework was still in 10% increments, when stock is 20%, changed the framework back to 20% and it installed successfully the first time.
Particularly if you have flashed ANY custom roms, because changing the battery framework is one of the most popular mods out there.
Having a different radio/kernel hasn't prevented me flashing an update yet!
Keep in mind that most of the "recovery" methods do NOT restore webtop and if you have flashed any updates from cheesecake you most likely don't have webtop anymore! The only way I've found to restore webtop is to grab the Zip and use moto fastboot commands in command prompt