Yeah stratus is right, very very picky. I personally would not say it is louder than a W7 though, nor sound as good. I am going out on a limb, but I think they changed the 9500s from the very first ones out because when they first came out, I got one and hated it, but recently I installed several and they were much better, or maybe I just got a fluke sub. I had the 15" 9500 and a 10" W7 though so that could have something to do with it.
Kicker imo would beat it in SPL from my experience with the two. Personally, I dont like how either of the subs sound, but if I had to, Kicker in a vented box would be my choice.