From IMSLP (my very favorite website in the whole Internet).
I will take a look, but from starters:
a. Reger and Franck are highly understimated,
b. Only a fool would think of holding any of this, so the question is really whether there are written in such way that they fit the hand with good alignment and without antagonistic muscle pulls, the rest simply being finding what is the right shape to render the music,
c. Melodic and harmonic invention is a tricky thing. I hate Alkan, but not because of the virtuosity, but simply because the lines and the harmony don't sound good to me; on the other hand, there is plenty of Czerny that I find quite lovely in spite of being so unbold.
There is no question that Czerny did not have the compositional talent of Beethoven or Liszt, and I suspect that Mereaux is closer to Czerny than to, by way of example, Franck, Berlioz or Saint-Saens.
But he gets a go at my music rack. Let's compare notes in a few days.