Hey, Sutty.
I just upgraded my 4.2.1 to 4.3.3 with sn0wbreeze. I had zero troubles (but I did follow, very closely, f4780y's very good and detailed directions!). It was very nice, having sn0wbreeze do all the work (it even adds the new gestures for you!). Very nicely done jailbreak.
I have a lot of tweaks that worked great on 4.2.1 and there are only two things that appear odd or flat out didn't work. Number one is YourTube did not like my 4.3.3 iPad. It always booted into safe mode - just by having it installed. Deleted it and it's fine.
In addition, iFiles doesn't play well now with 5-row keyboard. I understand you can employ a keyboard fixer tweak, but it doesn't help. The only way to type in iFiles is to temporarily disable 5-row keyboard.
Other than that, I am enjoying the upgrade. I don't know what tweaks you have that you might miss, but those are the only two I had/have that had any issues (and I've got most of the ones listed in the must-have-tweaks thread...
Hope this helps.
Marilyn