I upgraded specifically for the Airplay feature; none of the other features are worth $20, especially since I upgraded for $30 just a year ago. I also bought an Apple TV after the Mountain Lion announcement, preparing for MLs release and upgrade.
After upgrading today researching this "issue" when I didn't see the Airplay feature take effects, I was directed to the text on the upgrade page that states which Apple computers will be able to use Airplay. Airplay was sold as one of the big features of the upgrades - Apple previewed it during their event and it's highlighted on the OS X page on the website. So, why would a feature that benefits only a small percentage of usersbe trumpeted as a main feature?
Apple's big pull is that it just works. Plug it in. Setup is easy. It doesn't crash. You don't have to worry. Well, this upgrade just doesn't work. For the first time - and I've had 6 iPods, a Powerbook, an iMac, 2 iPhones, and turned my family into Mac users - I feel completely duped by Apple.
This is deceptive marketing at it's best.
I certainly am going to demand my money back. And I have no problem downgrading my OS back to Lion.
Heck, now I remember how furious I was after upgrading to Lion that I lost the ability to run PowerPC applications (which was supported by the Rosetta feature). I'll just add this $20 onto losing the use of $1500 worth of applications in my last upgrade.