On the 100hp module the 60hp setting seems to be the best, on the 100hp setting the engine response seems violent once over 2000rpm, I leave it on 60hp all the time, 30hp setting is not really noticable, nice to be able to turn it off though I rarely do, the difference in response between off and 60hp is unreal, especially on the low end.
On 100hp it took 2. 2 seconds of my quarter mile time and that was spinning the first 25' or so. If you plug the 7400lb truck into a hp calculator and then look at how much hp it would take to lower the quarter mile time 2. 2 seconds it is way more the 100hp. The XZT I am sure would be fine for what I use it for but for a little more the adjustable 100hp box I think is worth it.