I see it differently than your assessment as I have never had a problem booking Maui or desert properties at 8 months out. Westin Flex to me is more limited as it only gives priority to those two destinations (Westin Riverfront has barely any weeks in Flex and almost all of them are mud season). If those are the two places you always go to, it's probably a great choice to get priority if you need it, depending upon how many weeks are actually in Flex...not any OF, from what I recall on here. Sheraton Flex gets you priority for Hawaii, the desert, Colorado plus Florida and South Carolina, and for me personally I like the variety of priority locations should I wish to book during that period to ensure an earlier time stamp and better room location. Sheraton Steamboat is nearly all in Flex so if you want high demand ski weeks that's the way to go. To each their own, of course