Aruba has great topside amanities/activities and very good diving on the Southwest Side (not a ton of sites, but enough to keep you busy for a week) - reefs are healthy, tons of fish life and several wrecks (including airplanes). It's mainly boat diving - very few diveable shore sites. The tradewinds there also keep it comfortable, even though it might be hot.
Aruba is sounding more and more interesting! Does the diving tend to be rather "wavy and surgy" (or rough!) because of the winds?
Since shore diving is not common this may not be an issue, but is Aruba also plagued by the frequent property theft problems that are unfortunately so common on Bonaire and Curacao?