Looks like it. The X does also come in a 1" version. According to the tech docs, the only different components are the cups, which are round on the X but angular on the MX. MX also seems to come in a range of colours. So it looks like the MX is just a groovier, funkier version for those who like to colour match their components. X is more expensive though, and doesn't seem to come with the star nut and top cap.
I think the regular and "threadless" versions must be exactly the same thing that for some reason has been duplicated on the FSA website.
Oh yeah, and there's a 0.6mm difference in stack height.
