Hey man
I had a 2009 lmm duramax. I went with a DSP5 switch and Tunes from Duramaxtuners.com. WAYYYYYY better then the edge CTS Race I had prior or any other handheld tuner for that matter.
You can buy EFI live a few ways, if you purchase just the Autocal(which is EFI lives programmer) Duramax tuners will email you your DSP5 Tune. You load the tune onto the autocal via your PC, Then upload it to the truck. Very easy. EFI live is the BEST HANDS DOWN TUNING FOR GM's
Autocal
Just in case a your not familiar a DSP switch and tuning i'll explain. GM ECM is capable of handling multiple slighlty different tunes stored in the ECM and can be switched within milliaseconds. You install a small switch that has 5 positions on it. Each tune(switch positions) is different from eachother. The DSP5 switch is then wired off an wire under the hood by your ECM. Then you program your truck with the Autocal.
Once you install the switch and program the ECM, your done. Tuning can be switched on the fly. Unlike the handheld programmers(edge, banks etc) You have to stop the truck, turn it off, and reflash each time you want to change tunes. DSP5 is done on the fly. I use to have a smoke tune. I would Floor the smoke tune, blast diesel, then switch right away to my power tune and peace the fuck out.
Like i suggest, talk to the guys at Duramax Tuners.com ,they can sell you EVERYTHING you need. any more questions just ask