Ocean Divers has been in operation for quite some time. It may seem like I have a bias due to my alumni status, but full disclosure is that Ocean Divers far from lived up to their reputation during my stay. The only saving point for me is that I got their promises in writing before I paid! They have been running two cattle boats to Molasses Reef, the Duanne, the Bibb, and now the Spiegle Grove for many, many years and that means they have plenty of experience in what goes wrong in diving.
I like the fact that Ocean Divers has their course directors listed on their web site. Rainbow Reef mentions no course director by name. Even so, I would ask questions both by email and over the phone; how long have the CD's been CD's, how long have they been at that CDC, have they worked at other CDC's, will they be there when I am there (CD's take vacations too). Before you commit, get all their promises in writing!
I also like the fact that in the FAQ Ocean Divers tells you they do not dive in John Pennekamp State Park, whereas Rainbow Reef makes it sound like they dive Pennekamp. The way Key Largo is "built", dive sites are more than 3 miles off shore, because inside 3 miles the water is too shallow. Pennekamp State Park (3 miles and in) is a snorkel park and that full disclosure by OD says a little about their experience with experienced divers (we don't like to be misled). Rainbow Reef seems to use the Pennekamp ignorance factor as a marketing ploy.
Mostly, I really like that Dick Rutowski is the downstairs neighbor at Ocean Divers. Dick is the reason recreational divers use nitrox and his hyperbaric chamber medic classes bring a multitude of dive minds to the "round" table for the Sharkey's decompression stop (happy hour). Considering your SB handle, I can't see any reason for you not choosing Ocean Divers.
In case you didn't notice, I highly recommend every dive pro candidate get every detail and promise IN WRITING!