We spent a week in PR pre-cruise and I would say the beaches (obvious ones) were not as nice as, say, Bonaire or Aruba (we’ve been to many places via cruise ship). If you want to drive to Ponce or as suggested Vieques it’s much nicer. Depends on what you want really, Ponce is pretty nice and quaint, San Juan is big city and such. We were completely wiped out after a week (what vacation) because there’s a lot of things to see and do.