5.3L 2295E - immediately after starting programming, screen came up that was saving calibration settings, about 10 minutes later it beeped and changed to another screen that said please wait... storing data - waited an hour the first time, scared to unplug the POS
I finally turned the ignition off, unplugged the superchips, and the truck started...
So, I couldn't leave well enough alone - repeated sequence above and got the same results, but then I after I turned the ignition off and unplugged the unit, truck would turn over, fire, then die.
So, rather than disconnecting the battery I decided to try it again (can anyone here say COHONAS?)
Repeated the install for a third time, same results, now the truck fires right off again!
Being a software developer for several years, I now believe that the code behind this thing just didn't receive the benefit of proper testing with all of the different electrical configurations that are available on the AV. The unit appears to be well made from a mechanical perspective, no cheap connectors or anything. But, with all of the electrical gadgets available on the AV I think they just haven't tested all scenarios (i.e. Onstar, heated mirrors and seats, power this and that, RAP, headlights auto on in your garage, but not if you keep the parking brake on and don't release it after turning the ignition to 'run', etc.) There are even gaps in the manual: it says to turn the ignition to 'On', but there is not an 'On' position - there's a start, run, off, and lock. You'd think they could at least get the instructions right! Heck, there's even a post that Superchips asked someone if they could bring their truck over to their office in FL?!? Give me a freakin' break - this is a company that has been around for years and they should know better!
Believe or not I considered testing all of the scenarios I could think of (I disabled Onstar even though the instructions say nothing about it specifically), but decided I wasn't up for playing Russian roulette with my $40K AV's PCM! The unit never recognized that it had been ran before on my vehicle so it never went into 'recovery mode' or any of that - thank God because that's probably what's fryin' those PCM's (sorry guys). I did try the DTC's and that part seems to work. This is as far as I am willing to go.
I can say that I really appreciate Tom Byrne putting this deal together and supporting us, only wish it had worked out better. Given the rave reviews from those fortunate few that have got this thing to work I can say that I am still interested in this product despite Superchip's lack of support and responsibility for the problems. BUT - if it's the best one out there and they'll make it right then I'll be willing to try it again. For now, I asked for a return authorization and refund.
If you haven't tried installing it - DON'T! The only reason I did is I am too stubborn and was hungry for some chips. Instead of superchips, I had Lay's tonight. Lucky I didn't get cow chips!
On the bright side - I installed Stripeman cladding and tailgate lettering tonight - so it wasn't entire loss!
Anyone needing me to (eh-hem) say something in person, you just let me know! 
