That deal will require a TS presentation; they are good at obscuring it, but it will come up at some point before you pay.
The offer is worth about $450 (rough calculation) in savings. Is it worth burning a half-day of a 5 day vacation sitting around saying no to sales weasels to save that much? IMO, not worth the payback, or near break even, so not worth it.
The resort itself is really lovely and a favorite of many. In non-prime times you can find regular rentals there for a reasonable rate without the pitch though.
And if you do go, just say no to everything. They will make the Sheraton Flex program sounds great, but it is mostly a last-ditch effort to package up "mud weeks" at their various resorts that no one wants to buy. There are great ways to own Sheraton for thousands of dollars less than anything they will offer you.