I recently purchased two items on separate occasions from Procamerashop, a 6D and a 35mm F2 IS. Both items were far less expensive than any "official" dealer and both arrived within a few days. Unfortunately, the 6D had to be returned later because I got it wet and it failed. Procamerashop gave me the address to post the 6D to, an official Canon repairer in Colchester, UK. Procamerashop refunded me £10 of the £12 it cost me to insure and post it.
The repair shop seem to have done a good job, replacing some corroded parts, and returned the camera, taking about three weeks to do the job including postage each way. The warranty was voided because getting the camera wet was my fault, not a camera defect, and the sum total was £271.
So, all in all, I am very pleased with Procamerashop's service and will definitely use them again when the needs arise.
Having said that, also take a look at Panamoz for some very good prices too. Have used them before with no complaints and quick service.