True Tracs are nice diffs, however they do break. If you go to the strip only occassionally, or if RR/Autocross is more your thing, get the True Trac. If you want a diff that can handle 900+hp all day long, and can deal with extra NVH, tire wear, and jerkiness, get the C-locker.
I've daily driven my 98 with a locker for over 2 years now. It takes some getting used to at first, but you get used to it. Just make sure you don't hammer down in the middle of a turn at high speed until you learn the car--totally changes your line in a hurry.