The M5 is the only M with a Spot Meter, IMHO making it world class. Many need some TLC after this much time, but luckily there is Sherry who works wonders with them. They are larger than the traditional M body size/style which some people hate, but I think they are not too big. The shutter speed dial is perhaps one of the two handiest every designed (Canon EF was it's twin). The shutter is quiet like many other Leicas. Some people feel she hangs from the wrong side (her left) but the three lug version or operation (add-a-lug-to-me) corrects some of this. Many people (I'm one) think the read out in the finder is much better than the LEDs.
There was a deal a few minutes ago on the Classifieds for one that just had a CLA by Sherry for $900, this was a steal. It went fast.
Take a look at Stephen's classic camera section for some great reading on may different models:
He has a great page on the M5. I'd go black, but then I think Black cameras look better most of the time.