I too, own the lastest PC version and RealBand and BIAB. I don't work on my PC any longer.
I'm not partioning my Mac drive for BIAB or RealBand, nor am I purchasing another copy of XP or Vista to run it!
Every other program I need is OS X.
I think BIAB will fade for me. Logic is great and so is Ableton Live.
I'm somewhat disappointed in PG Music.
BTW: I got a FREE crossgrade to the lastest Mac 'full' version of Ableton Live when I switched to Mac from PC.
Respectfully,