Jan and Tom,
Sorry to be unclear. The PDAF will only work with the A mount lenses when adapted via LA-EA3 or LA-EA1 (the latter is only for APS-C lenses).
The original A7 series suffered from what I would think careless designs: the plastic claw of the lens mount on A7, the shutter unit that created shocks on A7R, etc. But, as Jan pointed out, the prices of the second generation was doubled for some unreasonable reasons. The RX1 followed the same path. So, the A7 II, now offering 14bit uncompressed RAW, seems to be an obvious choice for us.