I have not stayed there but have dived with them (as recent as may 2011)
If I were you, I would dive with them, but only do one or two trips with them, including if possible the Wednesday trip going to the Adolphus Busch wreck. They seem to go to the same places on the reef, even though they say don't.
They are the least expensive in the area, specially if you buy the "pay for 5 do 6 dives" card (I think that was the way it was called). Easy to do if you are in a group, they allowed me and my wife to split it, so we were able to save some more.
The captain and crew were nice but by the second trip the scripted jokes were tired. They have a 10-15 min trip out of the canal and they take that time while going out to do the briefings and coming back in to settle your concession tab that the captain runs on the boat(hot dogs, sloppy joes, soft drinks) independent of the dive shop.
They seem to cater to the infrequent or new diver. I found annoying that every time as I was going into the water they would stop me and check that my valve was open.
I would recommend you sit near the middle entrance/exits to the boat that way you can be first in the water. They are dependent on the high tide to come in and out of the canal (its very shallow) so they kept a tight schedule, when somebody stayed out for longer than expected it cut on everybody's subsequent dives.
Everybody on the boat gets a ticket for a draft beer or a soft drink at the tiki bar, and the allowed to go to the pool even if you do not stay there. The tiki bar was ok, they had live music most nights. The food was ok for a bar, but I have not found any great food in the keys. I would NOT even go to the "boondocks grille and drafthouse" a little further south on the other side of the road, the food was poor (frozen vegetables passed as fresh and overcooked fish)
I would also give a chance to dive with innerspace or underseas on Big Pine if you are in the area