Why not consider a summer trip?
I would try and find out who the naturalist and divemasters are on board the Sky Dancer, and how long they've been on staff? Experience has a lot to do with finding you the subjects you want to see. During our trip to the Galapagos, there seemed to be quite a bit of talk of the staff turnover PH had during that time (around the Belize incident).
When talking with the passengers who were aboard the Dancer during the same period we were aboard the Aggressor, they unfortuantely didn't share the animal encounters we had during the same days the boats spent while in the northern islands. We questioned how the Dancer guides apporached the sites which seemed much different than the Nemo, Aggressor who were there at the time. It think it all came down to the experience of the crew, and I feel lucky to have enjoyed the experience that we did.
I believe all the boats are well run and the accommodations are good for anyone's value. That being said, I believe the guides to be a focal point to the success of diving and capturing the essence of the area.
Hope you have a great trip, we can't wait to return.