For some reason this contains fi and fl ligatures, which look pretty odd on a monospaced font: http://imgur.com/4tJkbaK
I'd not spotted that before reading your comment, and went looking expecting a double-width ligature, which would be quite cool. Squeezing the ligature into a single character width seems sub-optimal for a monospaced font.
the first one would make sense as double width character, the second one should be single width to show, that the unicode point 'LATIN SMALL LIGATURE FI' is meant