My 2 cents
1) MFs are relatively reasonable for what you get.
2) Partial weeks or full weeks can be booked at 11 months by any owner; Premier owners can get on the wait list prior to 11 months (how far before 11 months depends on premier status) and those requests will get filled before open booking at 11 months.
3) You can book the specific week / unit you own between 12 months and 11 months (ie, before the wait list is filled) so you get priority for your specific ownership; beyond that, points are points.
4) Be very aware of what trust fund you buy into so that your MFs are optimized. If you buy a small package in Trust Fund E, you'll overpay. If you're buying lots of points, you definitely want to be in Trust Fund E.
5) Resort quality is uneven. BG has some top of the line resorts and lots of mid-range resorts. Know that if you visited Wilderness Club at Big Cedar or the Fountains, you cannot expect that kind of quality across the whole club.
6) If you care about the benefits from having authorized points, purchase through Boca. If you don't care about the benefits from having authorized points, still buy through Boca.
7) Study the list of benefits of buying authorized points and see if you think any of them are important to you. Personally I highly value the free cancellations I get as a Platinum member, but I could pay a lot of $35 cancellation fees for the price premium required to buy authorized points. Same with the wait list; I love it, but I personally wouldn't pay the price difference required to achieve wait list.
If I were buying for the first time today, I'd study the points charts and get a feel for how many points I'd need to do the travel I want. Find a package about that size and buy it resale, non-authorized. Ideally buy it at the resort you're most likely to visit on bonus time. If you can find a week / unit that you'd personally use full weeks at, great, but don't sweat it as the majority don't use that benefit.