I finished mine yesterday and im not impressed by the gains or the sound difference. My car is completely has a complete stock exhaust. I noticed a small gain in responsiveness and small rumble after 3500rpms. overall if you can weld at the house then maybe its worth it. I would not pay a shop 200 smackers to do this. I'm not discrediting what the original post says but I was excited as he was until I drove it and the performance described just was not there. Not being negative, just informative.
Thanks for the write-up, it did go well. One alternative we saw would be to do the cut and weld on the other side of the factory weld so you can put the straps over it and it does not have to be perfect, just flat.