I just installed a Banks cat-back exhaust on my '99 last weekend and am very happy with it. Quite a bit louder than stock but not overpowering and it seemed to take away the flat spot in 3rd gear that my Jeep previously had. The butt dyno seems to say that the Jeep has a little more pep but that could all be in my head since the majority of people believe that there's no noticeable power gain from exhausts. The install was a PITA though! Took me about 3 hours because I had to cut off the stock exhaust due to rust. A sawzall and cutting wheel will be your best friend during the install. Overall, I'd say do that exhaust if you're looking for a deeper sound from your Jeep.