Yep, got one of there level 2 in my 1/2 ton 4l60e. It supposed to stall around 2800, I havn't seen quite that, but otherwise no complaints. Its basically a reflashed 12" stock verter. Its a nice little bump in performance. Nothing like what your talking about though.
2004 GMC Seirra 1500: 3" Body lift, 295/75 Nitto Terra Grapler's on Stone Crushers, cam keys, Bilstein 5100, 5.3 liter, K&N 77, Stainless longtubes, Banks Monster Exhaust, Nelson Performance 93 tune, 2600 stall, Ls1 fans, Taylor wires, NGK tr55's, TransGo shift kit, Corvette servo, TCI pan, 4.10 G80 w/ TA Performance, Optima