ok ported boxes have a bass increase of 3db at the tuned frequency. which is in effect like doubling the power. but normally they can not reproduce sounds as low in frequency as a sealed. also, a ported box allows the woofer to travel farther through it's stroke, allowing more distortion for quick musical transients. so sealed would be a tighter bass note. sealed also uses less space. pioneer had a sub that would work in a 7ft airspace sealed, it needed 13ft for a ported enclosure.
as far as bass tubes. i have one in my car, and it is fine for me now. not too overpowering, but nice bass presence. i have had a custom bandpass box with 2 lanzar pro 12" that you could not stand to turn it all the way up while sitting in the car, and it only used 50 watts. it was funny when i worked at the car audio shop and these people had this notion that because i was 26 and was white that i could not have a loud car, but they were like shit, when they got in lol. was funny i laughed every time