For MTT's i'd keep it real basic. For STT's it depends on the games you play and the amount of games you play. If you play a lot, and of the same game, a detailed HUD will come in handy, if you don't, then just keep it simple as possible.
My MTT hud is simply, VPIP/PFR/3B/Hands.
Since your unlikely to really get any sort of sample on anyone playing in the low stakes games, there really isn't much point getting anything else. You can add a few more if you like, but most of the time i'd say it's detrimental. Use common sense and try to make assumptions about players, i'd think that would be way more accurate than some of the stats mentioned above.