Kerem Chemed 9 has a review of ShuT Chasam Sofer from the Hungarian reformer Leopold Low (Yavam is identified as Low in Shaul Chajes's useful Otzar Bduyei Sheimos in which he highlights the "critical" side of Chasam Sofer's work.
In HaAsif we also find a biographical sketch of Chasam Sofer that highlights the aspects of Chasam Sofer's thought that the Maskilim found attractive.
Followin is a great quote from L. Ginzberg, Students Saints and Scholars describing a necrology of Chasam Sofer written by I. H. Weiss ממזרח וממערב (unfortunately, only Vol. 4 is currently available online):
"Take, for instance, the last-mentioned scholar. R. Moses Sofer combined all the great virtues of the old Jewish scholar with fighting courage and determination, and therefore he was not only the head of a Yeshibah, but also the leader of a strong party, especially strong in Hungary, which opposed the new tendency in Judaism with success. It was not lack of comprehension of the new tendency that made Sofer its violent opponent; his keen vision gave him insight sooner than anyone else into the radicalism into which it would degenerate. And it was Weiss who, in his sketch of Sofer in the Hebrew monthly Mi-Misrah umi-Ma'arab (Vienna, 1896) meted out full justice to this great personality, although Weiss did not adopt Sofer's conception of Judaism as his own.
Moreover, Weiss did not descend to the manner of the so-called historians who are incapable of appreciating a great personality or a spiritual movement in its totality, but lose themselves in details and designate as characteristic the most insignificant points if they are bizarre, and the most unessential minutiae if they are curious. They judge accordingly, and as a result we hear opinions of the Jewish past and of certain tendencies in Judaism which, if the same logic were applied to the interpretation of general history, would give something like the following: Aristotle was a fool; he believed that the heavenly spheres were animated. Kepler understood nothing at all of physics, because he did not know so much as the law of gravitation, which is now known to every school-boy. And the fathers of the Dutch Republic were mischievous reactionaries, for in their political program they did not adopt universal suffrage"
I think this praise is overstated as Weiss throws in an attack on Chasam Sofer for being too pilpulistic in his Memoirs.
For those with an interest in Rabbinic graphology, I found an interesting collection of Rabbinic autographs from a periodical called Menorah (February 1927).