I installed my kit in about 90 minutes, went out on the road and did a couple of blasts and wasn't too happy. Popped in the old 108 chip, turned the boost up to 20 and whoooooah, this is a little more like it. Turned the boost up to 21-22 and was a happy camper. (this was with a stock setup)
So from the time I started the installation until I had a stock setup (turbo/injectors/intercooler etc) running 12.8 was about 2 hours. Now you can spend a long time getting it dialed in just right, but to get in the ballpark and have it running pretty good, doesn't take much time at all. I have since upgraded my setup and added an EGT gauge to make things easier.