I upgraded yesterday (baseband doesn't really matter to me, I'll likely be able to unlock it before I sell the phone in June) and let me tell you, it's a crap shoot. Hardly any jb stuff works.
Bitesms quickreply works (thank god) on beta 5.1 but the quickcompose causes safe mode to come on.
Tetherme works fine, fortunately. I think I'm gonna tough 4.2.1 out till it gets better because I like airplay and AirPrint so much. I need to tether at least once a week so if tetherme didn't work I'd be back on 4.1. Don't even try installing mywi, it crashed upon required reboot and I had to restore.
But no lockinfo, sbsettings, and a ton of other things I used all the time on 4.0 and 4.1.
Unless you have time and/or patience hold off another week or two.