Thanks for the advise on where to stay.
Islndgirl asked what kind of vacation I wanted - while we enjoy great company and and lots of laughs - partying all night is perhaps not our style. Because of that I think San Luis is off the list.
I am leaning toward the Aquarium. However, as I see it if beach and small venue is the top priority go to Isleno - Aquarium has perhaps better food and more "happening". Access to downtown is about the same.
By the way for those who have never visited the island take a look a Goggle Earth - it's amazing and helps you locate the hotels.