In case you're being serious, Amarok is highly unstable, bloated ("unresponsive UI"/"high CPU"), is a great academic example of extremely bad usability, and doesn't even want to start trying to compete feature-wise with foobar.
Amarok has been horrible since they redesigned it for version 2/ kde 4. Amarok 1.4 was the best music player I've seen and, I believe, one of the inspirations for foobar2000
foobar2000 was written by a former Winamp/Nullsoft contractor and the initial version was jokingly called "notepad" to emphasize functionality over skinning.
It's safe to say it has exactly nothing whatsoever to do with Amarok.
Yes, I'm serious! Amarok works for me. I use it on Linux and on Windows. I do agree with unstable (but not "highly" unstable in my case). Unresponsive UI is something I encounter seldom.