It all relies on a bunch of things to make it work

• You can plan (up to a year) in advance, as the earlier you can book, the more likely you can get what you want
• You understand that high season (ie school holidays, Christmas) has very high demand for the limited availability, while lower season may have lots of availability left, so you might need to flexible if you can't plan ahead
• You own enough to actually go where you want when you want for as long as you want -- 1500pts isn't very much
• You use it and don't let your annual usage you paid for expire
• You understand there are other costs to use it (ie transportation to get there)

the biggest path to failure is not being the early planner, as the longer you wait, the less likely the inventory you want is still available, and when the year ends, your unused vacation accommodation you paid for expires...