Okay, now that you've rescinded you have plenty of time to research and make a decision that makes the most sense for you.
Generally speaking, when you buy a Starwood resale, you will always lose the ability to convert your timeshare (TS) to StarPoints (SPs), which is Starwood hotel currency. (As an example, you can book a Category 4 hotel for 10,000 SPs per night.) You will also lose SPG Gold status, which is once again geared toward hotel stays only. They mean nothing on the timeshare side.
What you MAY lose when you buy on the resale market, depending on where you buy, is the ability to do an internal trade in the internal Starwood timeshare network, called SVN. If you buy a "mandatory" Starwood resort, you will still be able to trade in SVN. If you buy a "voluntary" Starwood resort, you will not be able to trade in SVN. Certain sections of Sheraton Vistana VILLAGES are mandatory; all of Sheraton Vistana RESORTS are mandatory. So if you want to use SVN, you must buy at a mandatory resort.
SVN can be very useful and valuable for trading to other resorts depending on where you bought and what season you own. What you should do is print out the StarOption chart in the Owner's Resource sticky and study it carefully. What you will find, is that a 3 bdrm platinum unit may not even be assigned enough points to get you into a 2 bdrm platinum unit at most other resorts. And if you buy a gold or silver season, the SOs you'll get are even worse. IMO, I'd never buy a mandatory unit in Orlando because I'd only buy there if I wanted to go there every year and the voluntary resorts can be purchased for a lot less.
Once you delve deeper into the system, I think you'll soon see that Orlando resorts are overpriced relative to other Starwood resorts. One other note is that it's very, very easy to trade into Orlando via II, or to rent a week via II Getaways for less than you'll pay in MFs.