OP, did you check here before ordering? The sub you have is a lot different than the ones you're thinking about getting. The classes are totally different. I own two 15H's and as mentioned before, they are very large subs. Make sure you have the room. I haven't heard the XV-15. Owners here like the sub. I can personally tell you that the 15H is a great sub but don't get sticker shock when you see the shipping charge.
If you were actually in the room with a 15H with a movie that has a good bass track, I promise you that you wouldn't think anything other than that this sub may have too much power.