(Sorry about the above post....I was half way through the post and I clicked the wrong button...I don't seem to have a delete option ?)
Roatan will give you some of the best (if not the best) diving in the Carribean/Central America, I don't think you would have any regrets.
It's definately worth taking time out and doing some homework into locations, especially if you are looking to base your vacation as a dive holiday. Websites and brouchures can be very deceiving regarding what they claim the actual dive sites are like.
I dove in the DR a couple of years ago, the dive op was showing me the usual pictures of Whale Sharks and even Humpback Whales that they claimed frequent their dives almost daily.....I swear to you the most interesting thing I saw on the dives where a bicylcle tyre and a few really scrawny fish.