Since ATT has decided to be a total **** to WP8 customers, I would flash my 920, but I have it set up just the way I like it, and don't want to risk voiding my warranty I'm pissed though, that moto X customers got their update today only 2 weeks after it was made available. I seriously can't figure out what's taking them this long.
I think Data Sense is an excellent addition. My phone (Lumia 620) updated fine today to Amber. Glance I'm not really bothered with, but my 'Other' storage has not reduced at all since updating. I was sort of hoping it would reduce but the phone seems to be holding steady at 1.25Gb free space.
One other thing I've noticed is that the battery life seems to have reduced by a few hours since the installation of Amber. This is via the battery life reading from 'Settings'.