I plan on sticking with RDS 5.5 until I see if MC is going to support the MAC version of Cararra, not just say they are. Been using it on G3/233 desktop with 288 mg ram & havn't had any trouble except in the mesh form modler which is a cross-platform problem. RDS 5.5 is a Big improvment over RDS3D, many more features and much faster renders. Don't think there are that many new feaures in cararra. I don't consider the UI a feature, it's an annoyance. I'd preferr to have other apps running and visible on the desktop without switching. Quite often I like to have another graphics program open with referrence material.