We've read through the reviews, so here's a quick digest of what people are saying:
David Pogue, New York Times:
Overall, Pogue thinks Mountain Lion is more than worth the $20 upgrade. He really likes the iCloud features that make sure contacts, calendars, email, reminders, and notes are synced up between your computer, iPhone, and iPad. However, he's not a fan of the new iChat replacement called Messages, which he calls "freaky, somewhat confusing."
