I just got my R-D1 a little earlier today -- it's much more usable and less toylike than I had expected. I'm actually quite impressed, the shutter doesn't rattle like is typical for Copals as used in the Bessas.
It works astoundingly well with my 35/1.4 ASPH. The camera doesn't have the resolution to pick up on the quality loss wide open at short distances, other than as a very slight softening across the frame. The 40/1.4 Nokt works well too, a nice portrait lens.
Unfortunately, the CV 21/4 isn't so great IMO. It's rather soft and muddy all over wide open and needs to be stopped down a stop even at infinity. Preferably two stops, it's pretty good at f/8. Not an available light lens. I love the small size and low price, but it doesn't do the job. It's a much better lens with film.
Same with the CV 15, except it's slightly crisper at center wide open. The image is technically usable IMO, wide open, or would be if it didn't vignette so severely. The extreme vignetting is persistent at all apertures and really not 'fixable' IMO. This is a fine lens with film, but not as suitable for the R-D1 IMO. Maybe the Digital M will work better, although I kinda doubt it.
So... I'm thinking ZM 21, at least for now. What I'd like to know is how it performs wide open and what its vignetting is like since it's a Biogon. The ZM 15 is a Distagon, so I'm sure it's well suited (except for cost and size). Maybe I'll get a ZM 21 to find out, it just can't be any worse than the CV, and CQ's $998 price is quite reasonable...