[ZipCordManiac]

This runs great. Unlike iTunes it doesn't check my entire damn music library on the NAS every single time or have tons of bloatware like Ping, iTunes Store, etc. iTunes took on average 3-5 minutes just to start. This starts quickly and immediately loads my music. If it gets updated with some decent features I'd use it exclusively. Another solution people might be interested in is Clementine.

http://code.google.com/p/clementine-player/

[mortenjorck]

Something has to be timing out with your network share. I have a library tens of gigabytes in size and a three-year-old MacBook Pro, and it the app starts in about five seconds.

iTunes is bloated; I won't argue with that—but it's definitely not slow.