That is a serious line of questions!
I have used sealed, ported, OB and a couple of variations on isobaric subs in cars, boats and the home. I have used sealed, ported and OB mains as speakers.
Horses for courses in my mind. And it largely comes down to what you like in bass.
For cars I am a big sealed bass fan. The inherent cabin gain tends to make up for any issue with the drop off of response of the box and sub itself.
For use with OB mains, I prefer OB bass.
Currently I am using ported mains, and a ported sub. The sub was rescued from a friend's failed boat experiment. It is a 12 inch in a 1 foot box, ported to around 40Hz. For fun I have corner loaded it in my basement, and it provides decent bass most of the time. There is one spot where the standing waves all collide, and it is muddy and boomy there, but that is not near the main listening area.
