I think $700 for an R-D1 is too cheap, desperation price? I'm putting mine up for sale soon (Need to pay moving fees) but intend to buy another one as soon as I have enough money to replace it again (Plentiful in Japan)
The R-D1 is a fantastic camera. I have used M8's before and prefer the viewfinder of the R-D1 (1:1 magnification).
If you like shooting with fast 50mm lenses you can attach a Nikon magnifying piece to the eye-cup and it magnifies the patch so much that you can nail focus every time with a very fast lens like F0.95/F1.1. You'll never miss focus when you use the magnifier. I use the magnifier all the time with my Jupiter 3 F1.5's and get pinpoint accuracy even when it's in a dark bar/night time.
If you like shooting with 35's on film, I would suggest using a 21 or 28mm lens.
A really cool benefit of the 1.5 crop sensor is that you can use half-frame lenses on the R-D1 and the photos will look fine. Here's one from a 28mm half frame Industar-69 lens.
morning by
James Burke, on Flickr
The only drawbacks of the R-D1:
1) Battery life (Treat it like you're shooting a film camera - you might get 50-100 shots per battery. If you go shooting all day and use the viewfinder a lot, bring around 2 - 4 batteries. The upside is batteries are only like $5 each on fleabay)
2) Low MP sensor, but this has never been a problem for me. Most people upload their photos to the net at far lower resolutions than the original RAW, and besides that 6MP is good enough for an A4 print or even a 2 page spread if the photograph was of good quality to begin with.
Support is not an issue, many camera centers will still take it for repairs and the parts are mostly the same as the Cosina Bessa cameras so there are plenty of spare parts to be had as well.
Agree with others that the R-D1's high ISO capabilities are FAR better than the M8. Shooting at night with the M8 is an exercise in frustration. You can go up to 3200 with the R-D1 by setting 2stops of underexposure while shooting at 1600. It looks like film grain, and all the tonality is still there.
My favorite digital camera for sure. If I had the money I might get an M9 / M whatever, but you can buy a car for what those things cost, no thanks.