We stopped over on our way to STJ twice.

The first time we stayed in OSJ and did both forts, a free tour of the governess mansion and grounds and just walked around the old city. We stayed at the el Convento and I can't remember the streets we wandered at night, it was a lovely neighborhood.

I would recommend both forts, each has its own charms.

Second time we stayed out by el yunque at the wyndam. We hired a local guide for a day. It was definately worthwhile as we got 100x more out of our hikes than we would have on our own. If you are interested, I have his info at my office. We did the bio bay tour as well which sadly wasn't as wow as I expected it to be.

I remember we all enjoyed our meals in OSJ every night and it was a fun place to bar stroll.