Thanks. It is very worthwhile moving tracks from Logic to Harrison Mixbus in my opinion for the following reasons, the workflow is extremely intuitive especially for those that use or grew up mixing on a console, eq, compression (limiter or leveler), tape saturation on every track, panning sounds much better, 8 sends per track, 8 busses available which also have eq, compression, tape saturation plus the same for the master bus. Finally, to my ears it sounds fantastic. The limitations are no software instruments or midi. So, yes it is worthwhile and easy to move your tracks into Harrison Mixbus. If you use midi / vst / software instruments just bounce in place in Logic as an audio file so it can be imported into Mixbus. Finally, I have found I use very few plugins at mixdown. Caveat, there have been some people that have found not all plugins will work in Mixbus, this has not been an issue for me. Prior to adding Harrison Mixbus I would do my mixing in Metric Halo's Mio Console ( I cannot say enough good things about this either and the people that run the company) and still do on occasion.
With respect to PI-101 WOS, it shows up with no issue in Harrsion Mixbus and works great. You can use it just like you do in Logic.
I saw that Harrison is currently selling Mixbus v2.3 for $39 which is ridiculously cheap. I've thrown away a lot more money on plugins over the years than that. They have lots of tutorials on youtube and google+, check them out.
Anyway, since this is the Two Notes forum, I want to end my reply saying that the C.A.B. is a wonderful tool for recording and I am quite happy with my purchase. No regrets whatsoever. It does what it says it will do and the company provides top notch service. I went with the C.A.B. over the Live as I already owned an awesome preamp pedal and thought it would be a great idea to gig or show up at a studio with a guitar and pedalboard. I haven't mic'd a cabinet since it arrived. Soon to make some IR's once I figure it out.
Scott