The El Conquistador has a funicular to get down to the water and then you take a boat over to their private island to get to a beach. It's a complete pain and not a nice enough hotel to make up for it.
Travel is fatal to prejudice, bigotry, and narrow-mindedness, and many of our people need it sorely on these accounts. Broad, wholesome, charitable views of men and things cannot be acquired by vegetating in one little corner of the earth all one's lifetime. Mark Twain
Ritz is in Isla Verde, is in the metro area - so if you want to enjoy the Isla Verde/Condado/OSJ area, then stay here. The beach is ok (nice, but just ok IMO). But you're close to the city.
I don't like the closeness to the airport, frankly.
St. Regis in Dorado is better in terms of a getaway, if you want more remote resort type feel. Dorado is definitely up and coming, the center of luxury (way more than Isla Verde), but it's far away (at least an hour or more depending on traffic) from the metro area. There's a lot of eco things to do around the area, but you're pretty much subjected to staying there (akin to going to the El Conquistador/Fajardo also suggested here). That said, the amenities of the hotel are geared towards you staying in the resort and enjoying yourself. So if it's a brief get away with the intention of pure relaxation and hanging out in the beach, then it's the better one.
I still prefer the option of going out and enjoying the city, so I'd still pick the Ritz.
The El Conquistador has a funicular to get down to the water and then you take a boat over to their private island to get to a beach. It's a complete pain and not a nice enough hotel to make up for it.
It's funny, we didn't think this was a pain, at all. Of course, we had a room at the very bottom of the hotel with the patios on the water, so maybe that's why. We never waited more than a couple of minutes to catch the funiculars, or more than 10 minutes to catch the ferry. We only did the beach 2 of the 5 days we were there, though. The other days we did the rain forest, a private sail boat charter, etc. I guess it depends on your plans, and where you are staying in the hotel. It's a pretty large property.
Just got back from Dorado Ritz. Go there. It is fantastic is so many ways. Great beaches. Get a plunge pool room in building #1. I have had rooms with plunge pools before and they always suck. The water is either too warm or too cold and it's never big enough to move around in. Some even end up more like a hot tub. This one is perfect. We used it constantly. It's great to have such close access to the beach. Room is very nice. Food is amazing. It's about 35 minutes from airport and Old San Juan. Went there for the day. Ate at a local spot called Cafe Puerto Rico. Order the SWEET plantain mofongo with fried pork. Your world will change. Lots to do at resort....DH took surfing lessons and windsurfing lessons. There are kiteboarding lessons too. Miles and miles of trails to hike or bike (they provide you with a bike). The service is the best I've ever had anywhere. My husband is a royal pain in the a$$....has very high standards for service. Too high, IMO. Always wanting to speak to a manager, etc. I cannot explain how well they placated him and literally changed his behavior with their responses to everything. Such a resort! Gosh... you must go!
Also: don't get a second floor room. The patio area seems smaller and it's not covered from the elements so unless you want to be in full sun until 4:00 or have to go inside because it's raining...get bottom floor with plunge pool. Mi Casa was good, but not even close to great. Best meals are encanto. Pool looked gorgeous but it was April break when we were there so it was like a big chlorine vat o crazy. If you have any problems or questions while you are there, ask for Ricardo the manager. So genuine, kind, and helpful. PS Al Roker was our next door neighbor and Pres. Bush's daughter Barbara. Ricky Martin has a home there and is often walking the beach. Keep an eagle eye open;)