There are some issues with the AOSP rom and with Paranoid Android by surdu_petru.
AOSP - It has that KitKat "feature" where apps can't write data to the SD card. This means that you cant download from your browser, do backups and use custom camera apps etc. The issue might be in the etc folder inside the permissions.xml file. Also when using the switches in the status bar (notifications/switches) you can see a bit of jerkiness.
Paranoid Android - There is auto rotation on the lock screen which tends to slash the cover art when playing music and it's slow, honestly it would be better to have a switch in settings or lock it in portrait permanently. Also there is the issue when the status bar icons "drop" when another menu opens and go back up when you close it (i.e. long press + widgets). The same issues persist in OmniRom.
Is there any way to fix these? Editing permissions doesn't work and I don't know how to fix the "drop" issue in Omni.