Finally after hearing everyone else talk about these things I broke down and ordered one for my truck. Todd said about 2 weeks till I get it and I can't wait!
Did mine in my driveway in about 1/2 hour. I'm NO MECHANIC by any means but it was simple.
Just look up the project and follow the instructions.
The only thing that was a little surprising was that after the mod, the truck ran at a very high idle for about 50-75 miles until the computer caught up. After that, watch your foot - it's real quick if your press hard.
After I got used to the initial peppiness, I got about 1-2 MPG better.