I know everyone here is breathlessly awaiting the next JBSourcery based on AOSP Android 4.2. I know I am. Some folks in another forum, however, have had nightmarish issues flashing 4.2 to their devices, and this is a short explanation as to WHY:
EDIT: I don't know if you guys read this or not, but it explains WHY the new TWRP 2.3.2.1 is required for a full Android 4.2 ROM:
Quoted from Androidspin.com -
"With Android 4.2, Google introduced multiple users as a new feature. In order to accommodate multiple users, Google is now giving each user a their own folder for storage. If you upgraded to 4.2 from 4.1, then the 4.2 ROM will look for a certain file in /data to determine whether it needs to migrate all of your files to the new multi-user data structure. By default, 4.2 migrates all of /data/media to /data/media/0.
A problem arose though with custom recoveries. A custom recovery retains the /data/media folder during a factory reset. When you factory reset and then boot a 4.2 ROM again, the 4.2 ROM will migrate everything in /data/media again. It will migrate your files every time you factory reset. This multiple migration is what resulted in some people having their files moved to /sdcard/0 or even /sdcard/0/0 etc.
In TWRP 2.3.2.0 we have corrected this problem by ensuring that we do not delete the special file during a factory reset. However, if ended up having your files upgraded you will need to move or merge them back into /sdcard. Also, if you have moved your TWRP folder from /data/media/0 to /data/media so that you could restore backups while using prior TWRP versions, you may now need to move the TWRP folder back into /data/media/0.
As a special note, if you restore a backup to a prior version of Android, you may have to move your files out of /data/media/0 and into /data/media to be able to see them again."
So the upshot of this novel is that you DESPERATELY need to upgrade your Recovery to a 4.2-compatible version in order to avoid problems when flashing from 4.1 to 4.2. I would strongly recommend TWRP 2.3.2.1: it's not only 4.2 compatible, but it's backward compatible with previous 4.1 backups, so you can restore those if necessary.
Easiest way to flash TWRP is to install GooManager from the Play Market, hit the 3 vertical menu dots in the upper right hand corner, and select "Flash OpenRecoveryScript". It will warn you and warn you: do it anyway and then agree to install TWRP 2.3.2.1. Your phone may or may not reboot. Mine didn't.
I find TWRP to be far superior to ClockworkMod in many respects, but I'm not going to bust on Koush's work, as I have the highest regard for him and used ClockworkMod for years. In fact, the newest version of ClockworkMod may do the same file management... I simply do not know. I will advise, however, that TWRP will NOT restore ClockworkMod backups... so if this is your initial experience with TWRP, make a nandroid backup with it immediately and before you make any fancy changes.
Anyway, thanks for reading my rambling dissertation. Hope this helps