They did the work on my Mark VIII.
Couple things to note.
1. Maybe they'll remember, but don't let them try to tell you that 2.5" won't fit. We had to argue about that. Then he tried to tell me that I'd lose all low end torque.
2. It might be a good idea to not have them weld it into a giant, single assemble. A pair of exhaust flanges would make it easier to work on the car in the future without having to drop the entire system.
3. Make sure you get his price in writing first. They promised me one price, then thought differently after the start.
The work was good, their reputation is good, but I don't think they are used to having someone who knows what they want walking in their and holding them to it.