The seller isn't likely to know what it sounds like seeing as its never been fitted to the car. It's got 3 silencer boxes though so I wouldn't have thought it was going to be stupidly loud.
The twin oval tailpipes look good as well and really suit a mk3 bumper, they look just like the ones on the Sebring backbox I've just fitted. I'd say give it a go if you can get it at a decent price mate.