ImCloud, I'm glad to hear someone has heard both and preferred the sealed. I own the SB13 and I've never regretted the purchase, but I wonder what the PB13 would sound like. A couple things you might consider:
SB is manageable to move by yourself provided you're average size. I know I couldn't move the PB13 by myself without slipping a disc. Or two. The SB13 is also smaller.
The black oak finish on my SB is much nicer than I had anticipated. A piano finish will show smudges/dust more, but I'm sure the piano finish is gorgeous too.
How big of a room are we talking, what are your listening habits? If you said gigantic room all movies, I'd strongly lean ported. If you said large/moderate room (or less) and a blend of movies/music I'd lean SB13.
Have you considered a pair of subs? Pair of SB13s would be nice