Not sure what the BEST forum would be but did you do a search on this message board? That's usually how I find information that I'm looking for. Also you might just google Cozumel and see what comes up. Trip Advisor usually has a lot of boards on different locations too. Hope this helps a little.
Coz site I surf this site for Coz info. Not as nice as cancuncare but still friendly and helpful. http://travelnotes.cc/tchatters Jimmy
Trip Advisor for Cozumel is http://www.tripadvisor.com/ShowForum-g150809-i66-Cozumel_Yucatan_Peninsula.html