The RZ II is a great camera. I've always been very happy with mine. Look out for the 110/28 lens. It's excellent.
It's a heavy camera and IMHO is best suited to tripod and mirror lockup use.
My biggest complaint with this camera is that I've always had frame overlapping problems with various film backs. Some are better than others but this was an issue that I was never able to have resolved, at least not by the local techs.