Just for an example of lens and 'sharpness' processing differences, here's some shots I was taking to compare a few weeks ago.
I was comparing the Canon EFs 15-85 @ 35mm to the Samyang 35/1.4.
Here's the shots I took under identical conditions on my 7D, firstly I RAW-processed everything with sharpness 3 using DPP. Basically, the samyang kicks butt. (shutter speeds were at 1/200s at f/8, so no motion blur, iso100, 100% crops from the far-right vertically-middle of frame)
Today, i've gone back to the RAW files, and processed the exact same photos again, with the samyang sharpness setting on 0, and the 15-85 sharpness on 5 (i tried up to 7, but it looked too 'over-sharp').
The differences are so much less pronounced than when the sharpness setting are the same. Basically, if this small difference in PP makes such a difference in the output photo, comparing across sensor-types is a lot harder than just looking at sample pics...