A preview of a review I've written on this app...
http://www.sundancemediagroup.com/articles/tracktion.htm

Overall, a big surprise from Mackie.

Wow, this thing looks great. The feature list is outstanding. 32-bit data, asio drivers, unlimited tracks, vst plugins.

I can't wait to check out the demo.

What is missing that makes you say this isn't competition with Vegas or Sonar for multitracking?

Tracktion doesn't allow the real in-depth level of editing that say, Vegas offers. Further, it doesn't have HD audio support that the higher end tools offer, doesn't chase or create timecode, doesn't allow for the minutae types of editing that the higher tools offer. But, it does have Rewire, which Vegas doesn't have and Sonar just got, does have a 'speed' of use that is surprising. I'm pretty impressed with how large it sits on the screen and how clean it is. No tiny, hidden tools.
Upsampling isn't as good as a Vegas is on sample rate or stretching, doesn't have the pitch shift ability, missing a lot of 'tweaky' things that are not used much, but are sorely missed when you want them. Envelopes are somewhat limited on crossfades, FX automation is a little kludgy compared to Vegas, Sonar, Nuendo, definitely missing some of the elegance of some of the apps out there. But for the price!!! Every school in the world should have this tool installed for kids to get exposed to multimedia.

Okay ya, pretty capable for $80, but I definetly like Audition/Cool Edit better.