The vendors don't have the best selection to finish out 2016, but there's always something out there to help better someone's build. With that said welcome to the final vendor reset of the year! It's all in one place!
You could do a free fall .. which I might try..but you have to know exactly the spot you need to get to. Unfortunately due to a driver update causing havoc I failed on a couple of recordings so have to revisit another spot for the next video.
A few times I've gone back down to play Underground. Though from Survival and Last Stand it was empty for grouping up. I liked UG as a pve dlc.
It would be good for UG to have a shot in the arm. Though, not sure ubi would revamp it, instead of a new greenfield expansion which would get more $purchases$ . They have Seasons coming to encourage regular play, the understandably it probably won't use other paid dlcs.