If people just want 4.2.2, they should be running Cyanogenmod. The T999 has official Cyanogenmod support, and CM10.1 is at RC2. T-Mobile has been pretty supportive of Cyanogen in the past (Twitter / TMobile: @cyanogen Ha. Good point. We'll ...).
I agree, though, TouchWiz adds a ton to Android. When I first got my T999 I installed the latest CM10.1 nightly and I was immediately impressed, but curiosity got the better of me so I made a backup of my ROM and then Odin-flashed the stock 4.1.1 (latest at the time) ROM back to the phone. I haven't even dreamed of restoring my backup; there's too much value added. This is my first Samsung Android device (i did previously have a Samsung Java phone with a slide-out keyboard and it was nice too) and I don't ever see myself going back to anybody else.