That's not an apt analogy. CF Express and XQD provide modern PCIe interfaces. Perhaps you are thinking of the archaic CF or soon-to-be-archaic CFast. My point is that yet another form factor with a similar PCIe interface is just annoying, though this appears to be an M.2 substitute. Ideally there would be two types of PCIe-based removable cards, a small and large. Of course we all know as with Beta vs. VHS or Blue-rays vs. HD Disc, nobody can agree on commonalities.