XDJ-XZ

I am considering the XDJ-XZ but I want to do my investigation before since I am also considering the Prime 4.

Today I have the DDJ-1k which I enjoy a lot but would be nice to have a stand-alone player also.

I can read a bit about crash / freezing issues sometimes related to USB stick speedratings. Other than that?  Is it a "stable" unit at present ?