I'm reticent to enter this discussion (due to historical experience on this can go) but since my name and findings were mentioned: I suspect that emtor is refering to
this blog post.
I took a few film holders (4x5) out loaded one side with 160 neg and the other side with Provia and took some shots. My intention for the experiment was to see what I thought about the images obtained from each stock when shooting outdoor landscape in Australia.
I used my Toho camera and changed nothing between exposures except the shutter time to account for the small difference between 160 and 100 ... essentially I gave it another stop for the 100.
I scanned both and found to my surprise that my Pro160 was giving me sharper results (as well as better shadows and colours I prefered).
These are reductions of 1200 dpi scans with my Epson 4870
Provia
160
If you're interested in my findings then please read the blog post. If you have different
findings please replicate my work and post your results, I'm sure we'll all be interested to see what others find.
PS - overall image showing the segment which the above crops come from
sampleSection by
aquinas_56, on Flickr