After clicking on the above link, click on Site Index, about 1/4 of the way down the full page, to see the list of MIDI files.
Regardless, before trying any other edits to the pianos, I'm finding that the files benefit from reducing the MIDI velocity greatly in Pianoteq's Velocity pane, essentially by reducing all of the velocities but keeping an almost straight diagonal, with the far right reading set to about 127, 93. (The exact settings working for me are 0,0 43,29 85,60 127,93 using the U4 Centered by Smilie. Of course, different pianos will benefit from other velocity settings.)
I tried to edit the above post to include this information, but there is no longer an Edit button for our posts. No way to delete the original post either, it appears. Is the site in the middle of a revision?