I think the font itself is quite nice. It has some inconsistencies that bother me a little, though. For example, the default flat symbol is thicker in the stem than inside the eyelet. The second f in the "sffz" ligature is different from the first. Having these inconsistencies doesn't make the font BAD, per se, just not to my taste.
Fortunately, in the source files, there were a bunch of other variants in his source files that were more to my liking. Here's the same score as above, but with my selected variants, as done in LilyPond.
The new font is available at fonts.openlilylib.org. Go get it! Here's a more extensive example: Grieg's Piano Concerto in A-minor, Second Movement.