and I am in... maybe it is just a mental game, but safari seems to be flying... and I was on Safari 6 for Lion before. The iCloud tab is great. I click on it, it saw the page from SatGuys I had opened (this one) on my iPad, and bam! I am on it.
Opened notes on Mac and iPad, added a note on the mac, showed up on the iPad in a second, edited it on the iPad, changes on the Mac almost instantly.
There is now an airplay tab on the top of the screen, just like in iOS, need to fire up the Apple TV and see how it does. ... And we are mirroring. Very nice. The resolution on the Mac changed into a 16x9 screen, with small black bars, but I can easily read this as I type it on my mac from my 40" TV.
Switching to video now... Loaded a 1080p video from Youtube, full screen on the Apple TV... looks great. Sound in Stereo, but the original was too.
So many possibilities for monitors with an Apple TV and a LCD screen.
I'd say this, ML is not a major overhaul to OSX, but so far, the enhancements seem very good. Airplay itself was worth the $20.