is mountain lion worth upgrading from lion

Go to Apple's Mountain Lion site and read the information, then decide for yourself.

That is a question you really have to answer...go to http://www.apple.com/osx and check the features in ML...are they features that are important to YOU? Do you want to text message from your computer? Use the other features that are an integral part of iOS/ For me the huge factor is the added speed of ML...Safari for me is significantly faster...the whole system is faster. I really like ML...but there are others on here who disagree.

Go through the features and see how important they are to you then decide.

To me, Mountain Lion is what Lion should have been - less buggy and faster. And, I like it even though I choose not to use some of the new features.