Complete opposite of the Surf Club. We stayed at both in Dec, first at Surf Club, and then at the Renaissance. Where our stay at the Surf Club had me never wanting to go back to Aruba, our stay at the Renaissance reversed my attitude completely.
Surf club is completely overbuilt, with a very poor ratio of public areas for the size of the resort. With the Surf club, you go out in mid-morning, and there are no chairs to be found by the pool, and you can barely see the ocean - just a sea of chair backs. The lazy river is nice, but except for the afternoon and evening - is always crowded.
Renaissance is more centrally located, and the private island is great. Only two downsides - rooms are smaller then the Surf club w/limited kitchen (ie. no oven). And no long beach in front of the hotel to walk on. If either of those two things are critical to you, then you might want to put up with crowds and go to the Surf Club.