My wife and I went to Bonaire for our honeymoon in November 2005. We had a super relaxing time and loved the island. In fact, we enjoyed it so much that we went back in May 2006 with my father-in-law, parents, and step brother.
The second trip was not quite as relaxing, but we were able to do 27 dives in six days and had a wonderful time.
I have also been to Roatan, the Keys, Grand Cayman, and Cayman Brac. On every trip I find myself comparing the destination to Bonaire and in my opinion they all come up short. The shore diving can be hard for some people to negotiate and it takes a bit more effort that boat diving, but I loved being able to dive when I wanted, where I wanted, and as often as I wanted.
I can't wait to get back. Reading these threads really gets me fired up for a trip!!