By "share" we meant "view in real time" (iChat Theater).
I have since "downgraded" both of my machines to Mountain Lion for this and other even more troubling issues with Mavericks.
1) Mavericks does not support ExpressCard/34 I/O from any manufacturer as far as we can tell. See this link for background - https://discussions.apple.com/message/23580033#23580033. This put us dead in the water for our video production as we use external devices that need this port to function.
2) Safari crashes or freezes upon launch. The solution: kill all extensions. Safari particularly does not like DuckDuckGo which I use exclusively for web search. Even with Mountain Lion, Safari crashes with extensions enabled. I now use Firefox and Tor exclusively.
3) Mail.app would not work at all in Mavericks until we disabled all - and I mean all - external accounts (those with external providers). Then we had to re-enable and configure each account. For those that were POP accounts, we first had to back up the mail directories with each host before deleting. We even had to log out of iCloud and re-log in. And from discussions we've read on TUAW and MacRumors users have had their GMail accounts disabled as well.
4) iCloud Key Chain does work but only intermittently. Updating of credentials fields is not instantaneous causing login errors.
5). Notes.app does not work any better than with Mountain Lion. Since we use multiple machines to post from, Notes can't seem to keep our posts updated or at all. In the past much of what we "saved" on iCloud has been "lost". Now we use Notational Velocity --- super.
These are some of the issues prompting us to move back to Mountain Lion. For us, Mavericks is a "wipe out".