Last night, after updating my iPad 3 to iOS 6 home sharing would not work at all, music nor video. Spent time with settings, making sure Apple ID and passwords were correct, rebooting iPad, rebooting iMac and updating Mountain Lion, verifying it works on my other iDevices running iOS 5.1, reviewing articles online and discussions here. NADA. I did a reset of my settings, nope ... No go. Decided to do a backup - reset all - restore in the morning(today).
Could not sleep, awoke around 2AM; rebooted iPad, iMac was already running and iTunes runs 24-7. AND IT JUST STARTED WORKING! Kinda. Did not do the reset of the ipad. Video appears fine, I've quit it in multi-task bar more than a few times, restarted iTunes a few times and video is good to go as before. However, in Music, the only thing displayed is Playlists, Songs, Genre. Completely blank display under Artists, Albums, composers. I have left it on oe of these pages for at least ten minutes in case it was a loading issue (around 17K songs in my iMac's iTunes library. ... This problem does not occur on the 5 devices (iPads 1&2-iPhone 4's still using iOS 5.1.) Its just as quick as it was before updating itunes. I've read some discussions on this site where it took 45 minutes or longer to load those pages on an iPhone 4S, also a large library. No way I'm going to do that. Will not be updating my other devices until that issue is resolved and I have more confidence with my iPad 3 and the new iOS.
Rather than keeping myself at this issue, I'll wait a few days peek at AppAdvice this weekend, then call support middle of next week if not resolved by update or Apple doing something with their servers or whatever.
Having to spend this much time getting the new iOS to where it is now is not what I've come to expect from Apple. There was plenty of time to beta; and if it is a function of their servers then its poor planning and execution. I'm a user, not a beta tester. Very disappointed. I use the iPad mainly for reading, video and music enjoyment. Sure I use some of the native apps for reminders, etc. but do not need it for business or ... Maybe it's time to start exploring Amazon's and Google's offerings for the next iteration of hardware and software. Too bad, but this is what secrecy & arrogance breeds ... Apple may be at its apex and will follow the pattern of Microsoft.
While I realize the previous paragraph is not going to fix anything, I certainly earned the right to vent on an Apple support forum.