When I went about 15 years ago I was warned about the drivers in PR. I was scared to death to rent a car in San Juan, but I did it anyways.
After tooling around San Juan and the northern/eastern part of the island for about a week I stopped describing it as "crazy" and changed that to "EXTREMELY aggressive and EXTREMELY polite".
Roads that here in the US had a speed limit of 25 mph seemed to be consistently going at 50 mph there. I wasn't sure why people even had turn signals on their cars, because they were rarely used. BUT, if I had to make a left turn from a stop that crossed three lanes of traffic (going 50 of course) CONSISTENTLY everyone "paused" and let me through. It was wonderful, and after about three days I just got in the groove and kept going 50 (and pausing when necessary) along with everybody else.
I've been twice. The first time I stayed in beautiful San Juan and didn't rent a car, and the second time I rented a car in San Juan and went exploring. As wonderful as San Juan was, I HIGHLY recommend exploring the rest of the island. Fajardo and the island interior were incredible and the beautiful photos posted by the OP make me want to go back that much more!
Peter T