Like others have said, the Renaissance is by the airport, so that would be out for me.

We enjoyed Hotel Arts last September. We had a basic ocean view room, which was very nice with a roomy bathroom, and our friends were upgraded to a 3-bedroom, 2-floor penthouse suite on one of the top floors. Spectacular with amazing views. We hung out in their room quite a bit. =)

It was great to be on the beach for walks and also for easy accessibility to dine around the marina a couple of nights. The marina restaurants are not the highest rated in the city, but we had delicious meals and lovely walks. We went to dinner early by local standards at 8:30-9:00pm. Most of the diners came to the restaurant while we were eating or as we left.

From Hotel Arts, we walked to Las Ramblas a couple times, and although it's a bit of a hike, it's a beautiful walk.

Even from our room on the 12th(?) floor, the bands playing at the beach late into the night sounded quite loud on the weekend. Something to consider if you're a light sleeper, although I'm sure there's also a lot of hustle and bustle (noise) in the wee hours when staying closer to Las Ramblas.

bsdstone mentioned he's traveling with his sons next summer. We really wish there would have been a soccer/football game scheduled while we were there, but there was not. What a cool experience that would have been for us, and might be for you and your boys on your visit.