I can say that the one Adventurer Collection trip that we looked into was the safari, and it <b><u>was</b></u> a decent use of points. Comparing the cash cost of the safari to the amount of points required, we were surprised to find that we were getting almost exactly $10 per point.
We decided against doing the safari (due to DW's bug phobia), and I didn't investigate further. So it's possible that there were deals to be had if you paid cash for the safari.
Still, though, it looks to be a surprisingly even exchange.