If you are referring to the old-school True-Trac, now known as Gleason-Torsen(I think) I would highly recommend it for general use, including the wife's truck. They are a strong and predictable limited slip differential which will lock and unlock on demand, not stay locked like a Detroit, or maybe stay locked or unlocked like a Trac-loc.
The only drawback to the True-trac is (if I remember correctly) they are only rated up to 33" tall tires. That being said, I thorougly abused one in a 10 bolt with 4.56 gears and 36" Cepek Fun Country tires, and never had a bit of trouble. I wish I still had that rig.
Jimbo