The fact that Sony is now included, is something I find interesting. While you cannot really give credit to the A-Mount, the e-mount to many is the epitome of mirrorless.
In bodies, maybe. In terms of lenses, it is pretty bad. And the corner sharpness (even on their $1,000 Zeiss 24mm/1.8 ) is poor.
NEX-7 and its derivatives (6, 5R etc) may be great camera bodies, but Sony E-mount is one of the least serious systems I'd consider, ahead of Pentax Q, Nikon CX and EOS M. Wow, that's pretty bad company now that I write it out like that; in sony's defense, they're a lot better than those three, just not in the same league when it comes to m43 (with its huge stable of lenses) or Fuji X (with a small but highly desirable collection of compact, fast primes).
Wind, Sand and Stars.