I just sent my deposit. I went with the pre-mapped unichip even though I have JBA headers, TRD duals, and a TRD drop in. From what I read the test 2003 Tundra is going with a RAPS kit and spintech muffler next. I just as soon not have the tuning for a RAPS and spintech loaded into my vehicle, and I don't see my exact setup being mapped by ship time. If I need to I'll have it custom tuned later.
On the flip side, I kind of like how the group buy is set up. Only the people who are 100% committed will put down the deposit, so we truely have an accurate picture of how things are going. Also, by the time I have to pay for the rest of the unichip, I will have forgotten about the $100 deposit. So it's really like getting the unichip for $650, Right?! It's like the rule on dating, "if you cant remember, then it never really happened."