It's called bonus time.
"Bonus Time reservations can be made online 72 hours in advance of booking by phone and a maximum of 45 days prior to check-in. A two-night minimum stay is required, and some resorts require a full-week stay."
https://ownerupdate.bluegreenvacations.com/news/take-advantage-of-your-bonus-time-benefit
Bonus time is always subject to availability. I understand that bonus time is difficult to get in the high demand seasons and at popular resorts.
"What is lost with resale points?"
1) Resale points do not count towards premier level status.
https://www.rocksvold.com/item/121-bluegreen-s-premier-ownership
2) They do not get "Traveler Plus" travel benefits (rental cars, air line tickets, etc.)
3) And resale points don't get network wide bonus time.
Many members buy a very small developer package which gets them #2 and #3, then buy all other points on the secondary market. That is, if #2 and #3 are desirable. Resale points never count towards the accumulations for item #1.
I have only resale points and I'm very happy with my account.
Many members seem to like bonus time, especially if they travel in the off season. They use points for Sun-Thurs (which have low values) and bonus time for Fri & Sat.
"Which property is better to be deeded at?"
Bluegreen ownership is not deeded. But every point is tied to a deed. My points are tied to three weeks at Seaglass Tower in Myrtle Beach. This means I get "priority time" for my weeks. I can reserve the week or weeks in the deed before the Club's reservation window opens. Also, I get bonus time at Seaglass Tower (because I have resale points, I get bonus time at only the "deeded" resort. Developer points get bonus time network wide.)
So, as far as I know, the only reason the deeded property matters, is, if you want to use the priority time. If this is important, be careful to verify the deeded time. Many points contracts in the last few years are tied to only a few days (2 or 3) and it is common that the days can be in differ weeks. This makes priority time basically useless. With older deeds found in the secondary market, this is less of an issue.
This web site is excellent:
http://bluegreentimesharesecrets.com/bluegreen-timeshare-owners-secrets/