I'd say Xtol beats the concentrate in those first two comparison scans both in grain and sharpness. The concentrate seems to have higher contrast or lower shadows eventhough the curves are similar and that makes it seem sharper, to me. I don't think it is anywhere.
Now i see there is a second set of commparison scans so
frame 15 xtol still beats concentrate in sharpness but one of the two has or seems to have better grain ..or different grain. Can't tell which. Obviously better in one area and reverses in another
I have xtol I mixed in early 09 and it still works. Whether it develops the same as when new, who knows. It's been reused after pouring back into glass bottle kept chilled
I still dont understand the need for a concentrate of xtol or amidol