I'll be at Cypress Harbour in January for a week.
I don't think I'd buy an Orlando timeshare (other than
DVC) unless you planned to use it most of the time. There are so many timeshares in Orlando it's very easy to trade into.
With Marriott, you buy a type of unit in a particular season. Then you make a reservation accordingly. You are pretty much limited to full week reservations. If you own a lock-off, however, you can split it into 2 weeks. 1 week in a 1-br, and 1 week in a studio. If you want to trade, you go thru I.I. For trading to another Marriott, there is a $79 fee. For non Marriott, I believe it's $129. You must belong to I.I. to trade. Marriott to Marriott trades get a preference within I.I. Marriott resorts are just about everywhere.
Hilton is a little more flexible, but they have far fewer resorts. Again, you own a type of unit in a particular season. That unit is worth a certain number of points. You can reserve the type/season you own 15 months in advance for a full week. Or, at 9 months, you can reserve using points at any resort, any season, any type of unit, for a minimum of 3 days. At 30 days, the 3 day minimum is reduced to 2 day minimum.
Hilton has 2 resorts in Orlando, 3 in Las Vegas, 1 in Honolulu, and 1 in Miami Beach. They have affiliated resorts in Breckenridge, Mexico, Scotland, and several in Sanibel, Marco, and Captiva Islands.
Hyatt is probably the least flexible. However, I haven't yet stayed at my home resort, but have stayed at most of the other Hyatts, so I guess it's flexible enough. It's just more work and more complicated.
Their system is a fixed week sytem, but you can convert your week into points. They have resorts in Sedona, 3 in Key West, Breckenridge, Beaver Creek Colo, Bonita Springs (near Naples), Lake Tahoe, Carmel, and Puerto Rico.
With Marriott, the affiliated resorts at Hilton, and Hyatt, someone has to give up a reserved week for you to be able to get it. That's why I say DVC is so much more flexible.
As for quality, maintenance, cleanliness, etc., I would say all are fairly equal, and on par with DVC. All are either I.I. 5-star or R.C.I. Gold Crown. (Both Marriott and Hilton have resorts that they didn't develop but are in their system. Some of these are likely t
be below DVC).
Hope this helps.