Lastly, I have never looked through a microscope at any negative, I have however seen tests done on Tri X & FP 4 developed with HC 110 and the Pyrocat HD. THese tests were conducted by a respected moderator on the LF Forum and bare out with striking clarity the thoughts I shared above.
This makes sense and is what I would expect to see. However I would add that XTOL is quite different than HC110. Although XTOL does contain a significant amount of sulfite and is still a solvent developer, it is both sharper and finer grained than HC110.