I have a 501CM with the new Acutewhatever (plain one). I also had a Bronica SQB (with the split prism screen). I owned them side by side for a while. If I was to pick one thing being the biggest difference between the two was how much dimmer the Bronica screen was. The split screen did make focusing quicker when it worked but it was also crap and darkened unless you were looking at it at the exact correct angle it was supposed to work so it wasn't really quicker, so overall I find the 501 a much better experience (focusing and everything else).
I use both a WLF and PM90 on my 501, with the prism whenever I miss focus is because I wasn't careful. I played with a RZ for a few minutes so I really cannot say whether focusing is easier or not. Have you consider a split screen for the Hasselblad? It should make it much quicker to get focus right.
I believe that Hasselblad lenses have their own leaf shutters built into them. I've read in the past that unless these are used on a regular basis, either these or the lens diaphragm can go "sticky" (I'm not sure which) I'm not a Hasselblad user, but it seems they don't like being left idle for long periods.
Perhaps users who may have experienced this could comment?
I will test my Hasselblad again, i may photograph the focusing screens i have but i hope i can do that in good way without reflection of light or over exposed the glass, i don't know if i have the Acute-D or Acute Matte, one screen came along with the body when i bought it and the other i bought it later to see if it will do better, not sure which is doing better now but both aren't quick or say reliable for me as my Mamiya RZ F.screen one.
And the second one is in attachments as a doc file, i drew it as i couldn't find a link for it exactly, that one has a little scratch on the centered circle but it doesn't change the face i have difficulty to focus smoothly precisely.
Just a thought, before you send it off.
Just check that the screen is installed the right way up. I'm sure it, is but why not have a look!
It is installed the right way up, i will not make mistake in this.
I wish to meet another Hasselblad user in my area if i can find and check if his/her one focusing better than mine or if he think mine is doing fine and i just have this wrong feeling about the focusing.
I haven't used the acute matt versions, but I really despise the standard screen. I use one of the microprism screens in one body, and a split image in the other. Either are miles above the standard cross-hair screen, IMHO.