I have no direct personal experience with the unit.
Mike @ Innovative Tuning seems to really be the go-to guy to talk to about the unit; he's had probably the most hands-on experience with it out of any tuner I've seen. He's pretty easy to talk to, so reach out to him (http://www.innovativetuning.com/contact/) I may end up going with the V88 when I get the new motor / rotated setup in (if so, he'll be tuning the car, because of his experience). A buddy of mine has a GT30 wagon with the V88 unit, and god it was a fun car, even though it's limited by 650cc injectors.
If you do go the ViPEC route, I'd strongly urge you to try to get Mike in for a tuning trip. Nothing against Keith, but with how many cars Mike has tuned on that system, I'd feel more comfortable with him behind the laptop.