Depending on where you live, it could be a big deal. I get my first 3 years free in NC before I have to start having emissions tests. As for the smell, kinda, but you get used to it. It's not much different than being downwind of most 70's era cars. When I first went catless on my FoST I wasn't a huge fan, but it kind of became addicting for lack of a better word. You don't notice it in the car unless your windows are down and the wind is blowing the right way anyways.