There are several timeshares in Key West. (7?) To me it is the location which is the defining factor. Banyan, Hyatt Sunset Harbor and Galleon are in what I describe as Old town, Hyatt also has two others as well as the two "Coconut" named timeshares. They are located on the far east side of Key West (I'll call new town) where the airport and the bridge to drive onto Key West are. These are far away from the Duval scene so you need to find transport (bike, cab, car not recommended). We like the old town locations because you can walk out the door and be in the middle of the restaurants, bars, music, shops etc. or you can stay on site for the relaxing day by the pool.
Banyan is what I describe as Original Key West, and Sunset and Galleon as modern Key West. Referring to the atmosphere and landscaping/feel of the property. Mostly studios and one bedrooms, the Banyan does have a lower maintenance fee, and that original Key West feel. There are units that have stairs leading up to them and some with a spiral staircase up to the bedroom. They have a small bar/food operation (run by a great person) two pools, one adult only and very welcoming atmosphere. The units are a bit quirky to me, not that this is a bad thing and smaller (but large for Key West lol) By comparison, Sunset is just about all two bedrooms, large units, modern Key West. Has a pool, fire pit, spa and nicely maintained grills, but no onsite bar or restaurant but everything is just out your door. And you can watch the sunsets from your balcony or from the courtyard/pool area. When the cruse ships were there (leave by 4/5 pm) they dock directly in fornt of the Sunset, and can make for a lot of crowding for a few hours on the road. But there are ways to avoid this crowd. The Galleon, never stayed there, but the do have restaurant and the Tiki bar is great, nice views. Location right on the marina.
We bought fixed weeks, because that is when we go to KW every year. Sunset and Banyan, extremely difficult to get into for most weeks if not an owner. Its hard to pick one over the other, Sunset or Banyan in my opinion, both have their pluses... One thing for sure the prices, renting is on a up cycle, expect to pay at least 500 per nite...maybe 400 but you may have to go in the hall to open your suitcase for those deals.