I have a 667 Ti with a 2 slot Magma, and have had no problems at all running PT 6.0, with OS X 10.2.4. It records and plays back fine, editing is pretty smooth. Its a little slower than 9.22 running 5.31, but OS X is just slower in general, so I don't blame PT for this. However, I haven't switched over for serious work yet--until Pitch n Time is there, it just doesn't make sense for me. Also, the cost of upgrading many plugs makes it rough, at a time of uncertain income. Waves wants $400, BF wants a chunk per plug (I'm giving up on them and their weird hostility), there are a few others as well. I'll switch permanently when I have a big fat budget to help pay for the upgrades. Until then, I'm doing everything in 5.31, except Beat Detective in 6.0 (which is indeed brilliant).