A ported box gives you a lower bass frequency, eg for music like snoop/dre, not so good for dancy tunes.
A sealed box would be better for dancy punchy bass.
That depends on what sort of dance music is it!
I listen to hardcore/oldskool and dnb, which is mainly all about the bass and has loads of low frequencies.
Ive got a 10" ported Vibe box which does the job perfectly
