Recently I have been using a modified version of NBUFN:
#define NBUFN 21 /* # of bytes, buffername, incl. null*/
I've set it to 41 and I can tell you it noticeably improves my editing
experience.
Now that some coding standards discourage arbitrary abbreviations and
filenames in some languages correspond to class names, it is commonplace
for filenames of source files not to differ within the first twenty
characters of the name. The problem is worsened by the buffer name
being plainly visible on both the mode line and the title bar where there
is plenty of room to display more information.
Of course I can make this change each time I compile vile but I was
wondering if the time had come to reconsider whether the value twenty is
still appropriate as the default for all users?