I had the 645Z with the 28-45 lens and used it for landscape. While I thought the sensor was incredible on the 645Z, the lenses to me were the weak link. At the same time, I got the A7RII with the OTUS lenses with an adapter and after comparing the two, I thought the picture out of the A7RII was better. I am waiting to go back to MF too but after owning the IQ180 for a while, the 645Z with its' lenses just didn't do it for me. The other piece of this was that I enjoy using a mirrorless system so much more than a DSLR now and do not wish to own another. Still waiting for the perfect CMOS back that can shift well on a tech cam.