I've dealt with them several times. I had them rebuild an old Automag i used to own. They have good communication and turn around time. The one thing I liked the most was when I received my marker afterwards they had a type written, detailed paragraph on the receipt of what they did to the marker and what was replaced and sent it back with the gun.
I contacted them not to long about having my current Automag serviced but I decided I didn't want to pay $50 to have them just change the o rings out so I did it myself for $16.
However if I ever need anything major done to the marker repair wise i'm getting ahold of them. Hope this helps.