Sharpness in real life usage may not solely rely on the technical specs of the camera. Most users of D800E with 36mp finds it challenging to produce consistent and really sharp photos, and majority of the technically sharp photos were produced in a studio environment with tripod and stationery objects, or landscape shots with tripod. This feedback is quite consistent from skilled photographers with steady hands, and thus making the 36mp not very practical in real life (if you are hoping for the super sharpness in every shots).
This is probably a good camera for landscape shots with tripod mounted, and a good camera for users with good patience and rock steady hands as good as tripod, as any slight movement will create bigger lost of details than other camera due to it high resolution. It will also be more demanding on the lenses used, as only highest resolving lens can optimise the 36mp resolution, just like the D800E, when only a few lenses are capable of matching the sensor.
It will be a lot easier for a RX1R to take a sharper shot (in real life use) as 24mp is more than sufficient for day to day shots, with a custom Zeiss f2 lens that matches the sensor.
Here's a good review of RX10, A7 and A7R.
Apparently, this is another professional photographer who prefers the RX10.
This is the review, making the RX10 looks really attractive (also click on A7 and A7R review that she has used for a week):
http://www.digitalcamerareview.com/...s=sony+RX10+image+gallery+fantastic+ultrazoom