As you know, I had the Mezzo with AV X Pre/Power as I do believe they were voiced as one.
Of course, I have heard them partner ATE2001 Phono/Pre & ATM211. This is a better combo if one had the PC1 Supreme where the ATE2001 clearly best match. Have heard other amps, like Leben etc, ... but if tubes are what you are going for Joe/Mike, this AT combo is simply superb. Not cheap but worth every cent.
I chose the X Pre/Power for the simple reason they are from the same company and designer and can't be wrong in the "voicing". Hope the info is of help.
Cheers and Merry Xmas everyone.