IDK, I thought the whole point of a deque was to string vectors into a linked list, so you get benefits of both, the most important ones being 1) cheap random access, and 2) insertion doesn't move stuff around in memory. I.e. that the deque's "vectors connected by pointers" is not an implementation detail, but the very nature of the beast.

Maybe I just took the boxes-and-arrows diagrams from C++ books too seriously.