On the JL Audio sub...
I believe (based on my ownership of the JL Audio E112) that JL Audio makes some amazing products if you have severe size constraints. They get amazingly deep bass out of such a compact form factor!
However, allowing a larger sub will provide some combination of improved performance & reduced cost.
My E112 actually had too much low bass after room gain was factored in...so much that Audyssey could not tame it (admittedly, I could only place them within 4' of the corners of the room),which is my other complaint - At the price of the JL Audios, I feel a sub should have some way to tune it through EQ settings. Look at images of the controls for Rythmik, PSA, and Hsu to see some of these options (SVS has it as well, but their's is in a menu LCD display - not as easy to recognize).