I've owned the RZ110 and more than one Hasselblad Carl Zeiss 110mm F2 and tried out the Mamiya/Phase/Schneider 110 2.8
All three are really good lenses.
The Mamiya/Phase/Schneider 110 2.8 is beautifully sharp excellent from corner to corner. The Bokeh is not particularly "characteristic" (for lack of a better word).
Of the three not the one to make a nasty busy background as "pretty" as the other two would. Doesn't have that hard to describe sort of "fantasy" look some bokeh's have.
If anything the weak point of this lens is the 5 blade iris that shows it's shape if you have to stop down even one stop
and have specular highlights in the background or just a really busy background. However on most backgrounds this won't show.
To see how damn good this lens is take a look at the downloads on the Phase one website. There is a portrait of a young girl. No fancy post work or anything. http://www.phaseone.com/en/Downloads/Sample-Images.aspx
The Zeiss is a very interesting lens, but not sharp or technically precise.
It is far from sharp wide open, but looks very very nice and the lack of sharpness is pert of the look. However it does take sharpening quite well.
The bokeh has a buzz to it that looks quite painterly, but can do some wierd stuff.
Center sharpness is great once you stop down to 5.6, but right in the corners its far from sharp.
Not a general purpose lens at all. I also noticed quite an inconsistency between copies of this lens.
I have one that is particularly sharper than the others I had particularly wide open.
The Mamiya RZ 110 2.8 is really good with nicer bokeh than the Phase/Mamiya/Shneider 110.
Stopped down bokeh is clean and less iris projection on specular highlights
Another lens to consider is the Mamiya 150mm 2.8D IF. One of the best MF lenses of all time. Does have a fair bit of brightness falloff in the corners wide open,
but so do many fast lenses. Sharp all around and very very nice bokeh.
Also the Hasselblad 100mm 2.2 is very nice. Closest I have found to my all time favorite the Fuji gx680 180 3.2
Here is a thread where the bokeh and iris blade issue was discussedhttp://www.luminous-landscape.com/forum/index.php?topic=67434.msg533454#msg533454
this is from that thread: