The OEM unit has clutches just like the aftermarket Auburn LSD. The trutrac is gear driven, so it does not have clutches that will wear out over time. The Trutrac is a better unit, but it all comes down to how much you want to spend to get it in there as apposed to the bolt in OEM LSD. In order to run a Trutrac in your truck, you would need a complete axle from an 09-10 as well as new gears, install kit, and ring gear bolts...or you can keep your current axle, and just replace 1 of the axle shafts, and get the aftermarket gears, install kit, and ring gear bolts.
The OEM ZF unit bolts right in to your current housing, and will only require the LSD and install kit.