I would definitely give AKR a try, just be careful about the time of year and what accommodation you choose. Some have no AC, just fans, which is fine as long as there is a breeze blowing at night. We were there once with a no AC cabana on the island, and there was no breeze for the first 2 nights and it was not pleasant to try to sleep. The diving is good, with a couple of big wrecks to check out if you are into that. Like I said, I don't think the quality of the diving is up to what LC offers, but it is a different kind of on-land experience than LC, with a great view from their restaurant and other things to do nearby on the island.
I have never been to one of the atoll resorts in Belize, but did a day trip to Turneffe from San Pedro once and it was very good diving out there. I would like to eventually make it out there for a trip, but the resorts seem to come and go and it is hard to get a read on which ones are really the best to try. I have MS and react to the heat with extreme fatigue sometimes, so there are times when I need to be able to go inside and cool off. So having a resort with no AC in the rooms, or only AC at night just won't work for me.
I know somebody mentioned Phillipines and Fiji, but one place we have been looking hard at and will probably do a trip to in the next couple of years is Lembeh Resort in Northern Indonesia. It is a good long trip to get there, but the "muck diving" they do and the unique sea life they get there is second to none in the world from what I can tell.