I just got the sony alpha 7 with kit lens. I was hoping to replace my wife's nex 6 with this since it will hold her 16-50 collapsable zoom and be a FF travel camera for me. Not the case so far.
Iq worse with apsc e mount lenses
Auto-mode wife would use starts the shutter usually 2/focal length.
Phase detect is poor or does not come on during low light.
The two main dials sit in front and back of shutter release making this camera akward to hold.
The grip is tall but way too shallow.
Lack of speedlites and lens choices
Finally the awb and standard picture style make the reds look orange.
Sooooo I grabbed my 5d and all I can say is ergonimics and good glass make the weight and size worth it. Like anything other manufacturers will follow but this needs time to evolve. Now I see the light on Canon's choice for the Sl1 and 6d since they are smaller and lighter but are more functional. I do own a sony nex 6 but again the lens selection is low and as said many times on this forum good Glass is important than just a sensor alone. Just my 2 cents.
1Dx, 5D3, 16-35 f4 L IS, 24-70L II, 70-200 f2.8 IS II L, Sigma 35mm 1.4, 85mm 1.2 ii L, 100mm 2.8L macro, 70-300 L, 40mm 2.8, 3 x 600ex rt, ST-E3