Sealed excels in transient response and group delay. It also allows a subwoofer to play to a lower frequency without loss of driver control. Excursion is higher with a sealed box than a vented box.
Vented boxes have the benefit of added SPL at and around the tuned frequency of the enclosure. Vented boxes offer lower distortion than a sealed box, especially at lower frequencies and higher volume levels because the port's activity limits driver excursion, while still adding SPL. Drawbacks are transient response and group delay, also acoustic phase differs by frequency. A ported box also loses control of the driver below it's tuned frequency, resulting in loss of driver control below that point and possible overexcursion if you play too low or don't use a subsonic filter.
A high pass filter usually employed 1/3 of an octave below tuning. For example if your box is tuned to 40 Hz a subsonic filter around 32 Hz would work.