No problems upgrading from the previous beta (11C48), GA-X58A-UDR3 + 9800GTX; however, I can't vouch for sound as I use an iMic. I still can't log in to iCloud despite the fact it's running fine on my iPhone 4 and iPad (i.e. not an account creation issue).
Reversioned and installed combo update.
I created the account in earlier betas ( c37 I guess ) // Now logged in iCloud from OSX c55 , then I played with a jailbroken iOS5beta7 on my touch 4G and set up that to also use iCloud for almost everything - and the first time ever I saw it working live. Everything on my iPod was also on the Laptop.mails,notes,contacts etc - without iTunes launched in between.
I don't liked the tethered jb and later faced some issues with iOS, so I reverted it back to official 4.3.5 and therefore have lost all iCloud related features naturally on the touch.
But OSX still logged on there and mail is working still. Only Apple knows if iCloud has now revisions of my iOS iWork documents together with my OSX iWork data combined hanging in their "cloud" , waiting for the iDevice to fetch it one fine day
Now I need to figure out how to get rid of iTunes10.5b7 and revert it to 10.4.1.. there is a time bomb ticking I think and also its now English UI only in tunes.. but ok, the price for having one night of iOS5 and iCloud syncing..
Later this month we can get it all is what I hear from those "trusted" sources. And that would be also the date for 10.7.2 final and iTunes 10.5 final. So.. tragedies/experimentes with only a short period to struggle with.