I haven't ever heard of anyone to avoid down there. I would take a look at www.padi.com
for the operations they sanction. They have to maintain a certain standard that should be an excellent mark for anyone to live up to.
I like to check out a minimum of three operators before making a decision. Ask them what their schedule looks like for the time you'll bee there, depths, type of sites, big animal encounters, etc... You will also get a feel for the personalities that you'll be working with.
This will help you make your decision and enjoy the folks you'll be stuck on a boat with while on vacation.