There is a lot of personal taste in subs that can't come from a spec. If you are into classical music more than HT, some people like the tightness of closed subs, if you are into HT sound, which tends to be more earth shaking, not quite as acurate, you may be better off with ported.

There is no perfect sub.

I am sure if you are into HT, you would notice quite a difference between what you have and say a LFM-1 (or 2).

2 Subs have a sonic value besides a higher SPL. I have two subs in a room about the same size as yours.