Weighing the pros and cons:
Black Pearl:
The Black Pearl would not look the same as Captain Jack's version. It would not have the infamous black sails and hull. Also, according to most people here, it's a galleon. We have galleons. Why have another galleon that just has a fancy title? Being paid (srsly.) to drive the BP I know it is hard to hit, though. But, I do agree, it looks alot more realistic. But, personally, I could not care less about realism in ship looks. Good things are, it is harder to hit than a SOTL. It is fast. Looks realistic. And, it is a famous ship.
Ship of the Line:
SOTL is my choice. It is big, strong, famous, and it looks like a 1700s version cruise line! I would love to sail a cruise ship, imo. Slow, yes, but think of it as a large galleon. Huge amounts of cargo, and for a long while (maybe even forever) people will pile onto your ship making plundering/SvS w/ public gunners alot easier. Having 20,000 health, it is a beast. I drove a SOTL in test b4 against a Battle-Royale, and we sunk. Full gunners. I'm not a bad sailor, ask a few people. So, it is not invincible. The game won't be that easy. If so, don't get one. Bad things: very VERY easy to hit. Not all that manueverable. Slow, and low levels will pile onto your ship before the helpful high levels can. Nothing wrong with helping a few low levels- but.. having that many... Eh....