The S300 is actually pretty similar to the PB12 in basic specs. You can take a look at the S300's specs at crutchfield (they don't sell it anymore, but haven't deleted the product page yet):
[Link: crutchfield.com]
The main things I like about it are it's low extention (22 - 120Hz +-2.5dB), 300W sunfire amp, and it just plain looks cool :)

I'm still undecided about my receiver, and was planning on asking about that too. But I figure that's another thread :)

Thanks for the input :)
-- Dave