I've been wondering the same thing. I'm sure some of the kit builders will jump on the 600 wagon with something. I just wish there was a bigger difference in the prices from a 600 to an 800. It almost makes it cost prohibitive when they are within 1300 bucks of eachother. The other drawback is having to stick with the 155 track unless you spend the money to extend, not a huge deal but being a big guy I'd really like to run a 163.