My wife and I have been there twice recently. It is a nice break from Minnesota
winter weather. Here are my thoughts... If you love sailing and boats then you really need two days. If you are a serious boat buyer or plan to buy a lot of gear
to take advantage of show prices then you probably need a 3rd day. 2-days gives you enough time to see everything, enjoy a decent lunch, have a beer
etc. without feeling rushed. The Strictly Sail show is in a great location with plenty of restaurants and tourist shops. If you are a serious boat buyer, then you should pay the extra to attend the "Premier" day to get better attention from the reps.
Lodging.... there are hotels nearby but it might be a decent walk to the sailboat show. One year we found a cheap
studio condo on South Beach for $100 and took a cab to and from the show. It was fun to stay on SB. We took an extra day to hangout on the beach.
Seminars.... most are pretty good. We enjoy them and always learn something and meet interesting people at them. We paid extra for a seminar to sail on a cat and that was ok, but not entirely convinced we learn much since the cat was very different (small&older) than what we are in the market for.