just got back from a 4 night stay at the Doubletree San Juan, and thoroughly enjoyed it.
Taxi from airport $16
I had a garden view room which overlooked the pool/gardens.
Pool is small but adequate, also whirlpool and a fitness room.
Free wifi (and wired) - you have to ask for the wifi code at reception
There are also two laptop computers to use in the reception area if you wish.
Easy checkin (11pm) and given cookie
Breakfast free for golds - good selection of made to order omlettes, or fried etc. Fresh fruit, and the normal hot fare, plus toasts, pastries etc.
There is a 24/7 supermarket opposite which is useful, and rooms have fridge and microwave.
Easy walk to the beach, or to La Concha (which is beautiful - about 15 mins) with their wonderful pools and private beach - Doubletree will give you a letter if you wish to dine at La Concha so you can book to your room. Also good casino there.

Would definitely stay at the Doubletree again.

Found staff very friendly and helpful.