Over the past 4 months, I've stayed at both the Bahia Mar and the nearby Hyatt. I will admit that the Hyatt was newer and fancier (and also a bit cheaper--we were upgraded to a suite when we stayed), but I enjoyed my stay at Bahia Mar more.
The location of the Bahia Mar is the main reason I would recommend it for most travelers, particularly those not interested in the literary history of the marina. You are within walking distance of the beach nightlife and the water taxi stops right there. We walked down the beach every day for breakfast, took the water taxi to Shooter's and Opa for dinner in the evening, then took it back to Beach Place and bar hopped back to the hotel. It was great. The pool bar has great food and drink specials ($2 drafts), but it does close early. We didn't eat at the deli or the hotel restaurant.
The rooms could use some upgrading, but everything was clean and well maintained. My biggest disappointment with the room was our ocean front balcony. It wasn't big enough to have a chair on it, but with the sliding doors open, it was a nice place to sit and watch the ocean and enjoy the breeze.
We didn't rely on the staff too much, as we like to explore and are pretty self-sufficient. We want to leave people alone and be left alone. The few times we did ask questions or need something, we were helped readily and the employees we dealt with were friendly.
As for Travis McGee and the Busted Flush from John D. MacDonald's books, I was disappointed because the concierge had no idea what I was talking about when I asked about Slip F-18. I didn't hold it against her though because she was very young, and I do have an understanding of my own literary geek-ness and that it is not shared by others. She pointed me in the direction of the F slips, and we went exploring. We walked the docks, but couldn't find the plaque. We finally stopped in the marina office/shop, and found out the marina had been redone. There was no longer a slip F-18, and the plaque was now inside the shop on display.