busses ? only 4 ?

If you're used to SONAR's audio bussing features then Project5 can seem really lacking at first glance. And if you're strictly looking at these mixing features, then I guess you're right--it does really lack when compared to SONAR. But Project5 is a softsynth studio first and foremost--not a multi-track audio recorder and mixer. It really has a different focus than SONAR.

But the good news is that SONAR is a fabulous add-on package for Project5. Use Project5 as a creative inspiration and a fantasticly fun instrument and rewire your Project5 creations into SONAR to use SONAR's mixing features and other capabilities.

The future of P5 is not yet written, so more mixing features might make it in some future release. Audio was not an option in the 1.x series but has been a very welcome addition to 2.x series.

ORIGINAL: MurderDethKill
that's the 2nd time I've heard Sonar referred to as an add-on

Yeah, and it probably won't be the last time you hear of it as more and more people discover SONAR.

and with freeze track / bounce track, thgere's the adddd option of searching out the audio folder and copying those audiop files into Sonar and having at it with the mixer

(if rewiring doesn't appeal to you)

it sounds a bit awkward, but I'm thinking actually less awkward than Rewire and w/o any cpu load. I may go this route when I begin to take mixing more seriously. I can't get into the track and midi editing model of Sonar, but I have a hunch I might be able to get into the virtual mixer.
That would be just about in time for when the virtual mixer View is added to P5