Here is an update on my sub hunting...
It turned out that the sale price for the supercube wasn't as low as I was told it would be. The price was $1000, so I decided against getting it. I think the sub sounds good but for $1000 it needs to be better than good... i should be blown away.
So since I have heard so many good things about SVS I figured I'd look into what they have to offer. I am still not completely decided yet, but the sub at the top of my list is the SVS PB2-plus. From what I've read this thing should literally blow me away! Anyone have first hand knowledge of the PB2-plus?