Rob, we have been to Aruba and dived there. It's a nice island with great weather (except the wind). It has nice beaches and a good mix of enough stuff in the way of restraunts and so forth without being too built up.
However, the scuba diving in Aruba is really very mediocre. The visibility is just good and certainly not spectacular and the sea life is skimpy compared to other prime diving sites.
You may be thinking of Bonaire. It is the B in the "Dutch ABCs" of which Aurba is the "A" and Curacao is the "C." We have heard that the snorkeling and diving in Bonaire is simply spectacular. Our local dive shop has a group diving trip going there over the New Years week this year and we are considering it.
The problem with Bonaire is that it takes forever to get there. The way the flights are arranged it takes as long (or even longer) to go from Indianapolis to Bonaire than it takes to go from here to Hawaii.
"A man never drinks anything that a plant lives in" --DBone (A Real Man).
http://vimeo.com/4938173