I've been searching for quite awhile to find tuning results for this engine.
I finally found something from KPE (I believe also partnered with IPF or something along those lines) and the results are pretty impressive if you ask me.
The graph below is from the XTS VSport, not the CTS-VSport and I think this is an AWD model. I'm looking forward to seeing results from the CTS RWD cars.
Green is stock. Blue is a stage 1 tune, and red is the stage 2 tune.
From:
http://www.cadillacforums.com/forums...uning-kpe.html