How was the quality of the diving? Thinking of heading there as well next month and diving with Rainbow. My one and only Key Largo dive experience was 30 years ago and the diving was not great. From what I am reading on SB the quality of the reef and marine life has improved in thirty years.
This was my first time diving in the Keys so I don't have any history to compare it to but....
Overall I enjoyed all of the dives and dive sites. We did the Benwood, Duane, and Spiegel Grove wrecks, as well as Five Caves. If you like looking at fish the diving was AMAZING!!!!! If you like soft corals, then any of the sites we visited were enjoyable. I personally like to explore complex reef systems, for that (and I was amazed) the Spiegel Grove was the winner. Lots of coral, a barracuda, a few eels, and a couple Reef Sharks.
The dive to the Duane was intense - current was ridiculous. Letting go of the mooring line on decent or ascent would have ended as a drift dive to Cuba. Couldn't explore too much of the wreck as a result. Definitely just beyond our comfort level of diving - but a good dive none the less, both my wife and I came back feeling that we are definitely better divers because of it.
All in all I will go again, and probably soon. Rainbow Reef was top notch across the board, from booking the trip, to having our tanks on the boat when we arrived, to analyzing the Nitrox mix in front of us, to having guides that actually cared about ensuring all had a good time.