HotRod,
Over the past weekend I had an opportunity to play with the newest Power Commander and I saw some difference in it and the Race Tuners tuning abilities. I wasnt playing it with it because I wanted to, but because I was trying to diagnose a ping in the top end. I still have the ping, but my fuel curve was flatter than it was with Race Tuner and the Torque came in a bit sooner. The numbers while not impressive were still a smidge better for less money with the same guy doing the tuning. My best suggestion to you is to get a stage1 download and then implement the Power Commander so you can at least get home if the Power Commander ever dies on you.
Hope this helps,
This was the PCIII usb version. You can buy it online for under 300 dollars. Download is i think around 160 dollars and then whatever your tuner charges I am guesstimating around 250 dollars.