JDM_BeebstaI believe you are mistaken. The 960 and 950 are indeed M.2 ssds but that refers only to the form factor. The still communicate over the PCIE bus.
J0SHFully agree. However when we talk about PCIE people refer to the slot itself, not to the bus. So even though M2 slot used sometimes the PCIE bus, is just an M2 slot. The point is the same, makes no sense to compare SSDs designed for PCIE slots with SSDs designed for M2 slots. People with desktops most likely get the PCIE slot ones, people with laptops will get the M2 ones. Yes, there are desktop mainboards with M2 slots, but is cheaper to purchase PCIE SSDs or SATA SSDs with an obvious impact on speed if they go the SATA way.