I had some relatively high hopes for Pie after his first season in an O's uniform, when he hit .266/.326/.437 in 2009 and showed plus range in the outfield. While not expecting star level performance ever, a league average hitter with a +10 glove in left-field is a nice little player to have on the cheap. Pie had improved his plate discipline that year, cutting down on his strike-outs and getting his walk rate to almost average.
Then things got worse instead of better in 2010, with fewer K's - something I think the team was trying to have him work on - going with less power and only half as many walks (.274/.305/.413). The defensive metrics were less kind as well.
This year was worse still, with no power whatsoever (.220/.264/.280) and a -11 UZR. His -1.9 Wins Above Replacement was one of the lowest marks in the majors.
Pie always seemed like a guy with good tools but not great baseball skills, who sometimes didn't seem sure what he wanted to do. Occasionally he'd actually show a good approach at the plate, but often enough he'd go up either hacking at everything or (though less frequently) trying to be excessively patient without quite the pitch recognition skills to make it work.
It's a shame that Felix wasn't able to reach his ceiling in Baltimore. Maybe some other team will pick him up and give him a chance - he is only 26 years old, after all.