Q vs SSD/Port vs Seal

[buickid 0]

Alright, so we're looking at a street beater type car here. I'll probably be running the 1500D @ 1/2 an ohm, which puts me somewhere over 1500 watts. Now as I understand it, the SSD tends to accentuate the low-lows, while not being as loud on the higher lows. How does the Q stack up to that? I'm looking for a sub that will get loud, and get low.

Then, I'm not adverse to a sealed box, but I was wondering how much it will reduce my SPL. As mentioned above, I like to get loud. Sealed looks particularly enticing because of the smaller box needed.