We are definitely all spoiled by modern af.
I suspect they didn't design in enough CPU horsepower to handle both the digital path work and the af speed to make it comparible to more modern designs like the Nikon D700 let alone a D810. To me, the af speed is around D200, maybe slightly below.
A Merrill redux using the CPU equivelant from the Quattro would most likely improve the sd1m.
I would love to c live view added as well. I could remove the ir filter and shoot full spectrum or do 720Nm ir and use live view to focus.. I could shoot ir w/ the sd1m, but I would have play games to get accurate focus or shoot everything at infinity.
Panasonic LX100, Sigma Foveon, Fuji X and Panasonic CM1