About data usage, take a look to page 104. Maybe it helps.
Installed a few days ago, lovely smooth experience.
Only problem is battery drain - I had the phone charging overnight and now (midday) it's down to 20%.
4h 38m 38s on battery
Mobile standby 59%
Phone idle 32%
Android OS 2%
This is with data enabled, without it I get ages. Thing is, I bought a smartphone to have a data connection!
Any ideas why? My data bundle is expired at the moment, could that have something to do with it? If I can't figure something out I'll have to go back to CM9...
The battery status in settings is crap (at the moment).
It tells me about 59% usage by bluetooth - i NEVER user bluethooth.
Try e.g. GSam Battery Monitor.
But over all, new JB featueres like Google Now drains more power.