Mid-Jan/Feb/Mar are always popular for warm weather destinations as mainlanders escape the cold. And it's also whale season on Maui, so it's especially difficult to book during these times. A few years back, I tried to book my home resort (WKORV-N) in February and was squeezed out.
Since Starwood coded the entire year (except the last 2 event weeks) as platinum, that means that every float owner has the opportunity to book those high season weeks, which makes competition especially fierce. Fixed week owners can take up to 25% (?) of the inventory and that will never be available to book. Multi-week owners can daisy chain several weeks together. And, of course, Starwood owns inventory itself and can presumably pre-book these popular weeks. (We don't know this for a fact, but it was theorized after all inventory was booked for President's Day week even for owners who tried at the earliest possible moment.)
With exchangers now able to bank SOs, the competition for any high season weeks that happen to hit SVN will be grabbed immediately. So you need to be persistent and lucky if you want to get a high season week as an owner and very persistent and very lucky to get in as an exchanger.
FYI, I believe that Marriott owners on Maui and Hilton owners on Oahu have experienced this situation for years.
IMO, the only thing that might swing things around at this point are airfares skyrocketing and/or the economy failing. But I certainly don't want either of those things to happen.