Should I have my Canon 30D serviced? It has taken about 7000 pictures, went round the world a couple of time and it seems that the AF is a bit slow, but the picture it takes are still of a very good quality.
If it ain't broke, don't fix it, unless it's been near salt water or sand or anything like that.
I had to send my 10D away, and I used Lehmanns who were reasonably priced and with a quick turn around. Fixation are right in the middle of London if that's better for you, do a lot of pro stuff.