5D with Leica R lenses?

Hi People,

I was wondering if anyone here has any experience shooting with the 5D mk1 or mk2 and Leica R lenses with an adapter. I'm especially interested in how accurate did you find manual focusing to be and what viewfinder screen you chose for this. I'm not worried about speed, I'm used to manual focusing my Leica Ms and Nikon FM but I'm more worried about the accuracy...

Also can you honestly say that you're getting better results from Leica R glass than Canon EF? which lenses are the best in the R lineup? I mean I know from experience that Leica M is massively superior to my Canon EL (even L) glass. But I never used R lenses and not sure how what to expect from them...

Basically I love the Canon sensors but I really feel that the Canon glass and very poor and unreliable AF lets these cameras down...

Any opinions will be very welcome

Thanks