There seems to be an undo prejudice against the ported sub that can reach down to 19hz. The technology via computer aided designs makes them pretty damn good and nary a difference in tone from the sealed subs. However, cabinet size may be the deal breaker and unless you listen to a lot of pipe organ music, will never need to go below 24hz anyway.
Both would make great choices.
Jim
There is very good reason why ported subs don't get as much love as sealed units. They are simply not as accurate, period. If you just want you system to sound like the local garage band at the pub, that's one thing. However, if one has accurate high end equipment (which many AC's have), the ported units are not going to sound as accurate as the sealed units.
I went through this at length with Mr. Mullins of SVS Audio ( a very nice guy who knows his stuff). He was adamant that for systems that are primarily music in moderate size rooms, (with high end speakers and electronics) the SB 13 Ultra stood alone. So far, my auditioning of the SB 13 Ultra has confirmed his analysis in spades. Until you hear one, it's hard to communicate effectively just how different it really is.
If you are working with a very large room, then yes, ported may be the only real option.