I updated my iMac to the new Mountain Lion operating yesterday without issue. My machine seems to be functioning pretty smoothly but I have to say I don't see a great deal of difference between Lion and Mountain Lion. There's a couple of new applications on my dock: Reminders and Notes and I noticed that there's also a couple of small changes to the Time Machine interface. One of the things I'm a little aggravated about (and one function I was actually looking forward to with the upgrade to the new OS) is the Airplay Mirroring feature which is supposed to allow you to mirror your Mac's display to your Apple TV. Unfortunately, it doesn't work with my iMac which is slightly more than two years old and unless your Mac was manufactured in 2011 you will also be equally frustrated. Is it that my Mac's hardware is too out of date to be able to perform this functionality or is Apple simply trying to get me to purchase new hardware to get the latest and greatest features by rendering my current Mac obsolete? I think $19.99 was a more than fair price for the upgrade to Mountain Lion but this issue leaves a bad taste in my mouth. Especially when there's 3rd party software called Airparrot available ($10 bucks for the app) that can accomplish what the revered Mountain Lion cannot. Just to be fair and balanced, here's an article that explains why your current Mac is unable to take advantage of Airplay Mirroring.
Mike Beeferman is a technology nerd and consultant at large in New York City and Brooklyn. He even makes house calls.