Ported or sealed which is better?

[sonic_debauchery]

I ran across some new subs from the nsd line from svs today that were sealed and the literature said they go very low for a sealed subwoofer.

This leads me to a number of questions:

1 Which is better for low frequency couch shaking
2. Which is better for music
3. Which is better for movies
4. Does one have a tighter more accurate sound than the other
5. Is it a preference or left upto ones own ears

Please help answer some of these questions.