Hello,
I'm using a 503cw with a P25, and yes, it works. Lenses are still great, I did some tests with a P45 too, and results are marvellous too.
Sharpness may be an issue. I think you will have to do some tests.
I do studio, no weddings, no fashion, no handheld. I get sharp results without problems (and I don't consider having good eyes), but of course, this is studio, there is a lot of light. But I wonder if AF is not a way to go in some years.;-(
I used to do some documentary, handheld location work (personal projects). 1/60 is a no go for me, you need 1/125s at least. I am used to do some 1/15 handheld with my D2xand it works fine, but with MF, it's simply not possible.
Tom