I had a torque flow exhaust a couple of years back on my clio 172. Tbh they did a pretty good job on it, the only problem was they made the exhaust 2 inch diameter instead of 2.5, although I didn't know what the optimum was at the time.
Ignoring that, I never had any problems with it in the 2 years I had the car and once decated it sounded pretty evil.
Its worth noting, they did shut down for a while and have only recently reopened from what I've been told by a friend who works in the trade.