I have the R-D1 for more than a year now and now problems so far. I had to adjust the finder, but with the advice from the threads in this forum this was quickly done. It is still very slightly tilted but I doubt that this has/had an impact on precise focusing. Among the other host of useful information on Rich Cutlers excellent
R-D1 site you'll find some notes on R-D1 service in Europe.
There are many aspects to judge a camera: reliability, ergonomics, file quality, price, brand and whateever else somebody may choose. Looking through the forums my impression was that at least the ergonomics of the R-D1 are considered to be a little superior to the M8.
Usabilty of a camera is often underrated. If it's difficult to use a tool it's difficult to get good results. But that again is more a matter of taste. For me the R-D1 is a pretty much classical camera and I like that.
Regarding "file quality" I think the M8 can produce "better" results. In my opinion better means mostly resolution here. But it depends on what you want to do with your files. If you wan't to do large prints my personal experience is that up to 60x40cm there is no major problem with the R-D1. This should be enough even for exhibitions. As some other poster here said a while ago the increase of resolution is more evolutionary than revolutionary.
The swan shot in
this thread is on my wall at home. It was processed with Lightroom and PhotoZoom Pro and printed on an Epson 9800 at 60x40cm on Hahnemühle Photo Rag. To me it looks beautiful ad I doubt that with the M8 the result would have been so much "better", whatever better could mean here.
Nevertheless I have to admit that I also like to own an M8, but I still can't afford it. And at the moment I doubt that I'd buy one If I could. I'm not sure if the advantages justify this enormous price difference. This may be clearly different for other buyers.
A footnote about the ongoing discussion about "file quality" everywhere on the web: two weeks ago I was at the HCB Early Works exhibition in Munich. They had about 30-40 pictures from the early thirties, all enlarged to about 60x40 cm. If you do "pixel peeping" with these prints the result would be some like the following: some seem to be out of focus, some apear very soft, sometimes there is a lot of noise (years ago called grain), some have halos and pictures with razor sharp micro details are mostly missing. So what? These pictures are brilliant masterpieces even if their "file quality" wouldn't stand today's "requirements" of many posters out there on the web. To a great extent the discussion about minor file quality compared to that of the M8 is ridiculous. If your image isnt good, Mega Pixel won't save it. If it is good, Mega Pixel are of minor interest. More Mega Pixel won't let you take better images.
Thumbs up for the R-D1. I like this camera very much and it fits my needs very well. Try it. If you don't like it, it's OK, take another one. If you like it, be happy with it.
And don't forget to post some pictures! ;-)