Ansa is a cheap replacement exhaust that will last a couple years and then rust out. Most of the time they have a tinny sound with a few exceptions. I think the 320i Ansa is perhaps ok. I didn't know they made one for the E34.
If your stock exhaust does not need to be replaced, leave it alone as it is not a performance upgrade to replace it. The only thing gained is that most replacement exhausts weigh about 20 pounds less than the stock exhaust. They do not flow any better.
Mike Holbrook
Meridian, Idaho
1992 535im, 17", Euro M5 Throwing Stars 8's & 9's, FK-451 235/45s & 255/40s, M5 Sway Bars 25/20, Conforti chip, Lowes Ram Air, glass sunroof