Good choice. Emails to/from Belize can sometimes be intermittent but Ramons has been around for a long time, even survived a major fire a few years ago, but Dive Haven, not so much. I'm sure you'll have a good time at Ramons but less sure about Dive Haven and there's even the potential for disaster, imho.
That said, a large group trip would probably go well and I say this based only on the reputation of the owner as a host/businessman along with a few trip reports.
While I don't have concerns with regard to the owner's desire to ensure his guests are well taken care of, I do have some about what may be an overall lack of concern for the environment as a whole.
If we consider this huge resort built in such an area, and know that he built it there because of his love for the local diving, maybe we shouldn't look too hard under the carpets.
On the otherhand, I'm hearing about another one if not more resorts, going up improperly elsewhere and these are skirting environmental impacts. At this time, I caution you to take my post as a loose rumour only.
It's my intention to dig deeper and if found to indeed be true and indeed be these new project(s), other than Belize Dive Haven, I'll return and let you all know either way.