Yes. I took a Sigma 1.4TC there for repair, my Sigma 100-300 f4 for a service and my 120-300 f2.8 is with them at the moment. My 50D went in with a sticky shutter button as well.
Very friendly, especially the guy with the longer hair, and I'd recommend them. However, isn't there somewhere closer to you. I prefer to drop things in and receive the personal touch.