On Tuesday, Apple boosted iTunes to version 11.1.3, in the process fixing some problems with equalization, large libraries, and other minor bugs.
First off, the update resolves an issue where the EQ might not work as it should. Not very descriptive, I know.
Second, Apple says iTunes 11.1.3 improves performance for those with large libraries when switching views.
Lastly, it offers oft-cited-yet-unspecified "additional minor bug fixes." You can download the update now via Software Update or from Apple's Featured Downloads page.