Is OSX Mountain Lion worth getting?

I am currently running Lion and I have felt letdown and neglected since upgrading. I haven’t gotten enough updates, and the updates I have gotten, have not fixed the issues I am experiencing. If anyone is already running Mountain Lion, let me know how you like it. I am particularly interested in “tabs in the cloud.” I have been wondering if this is compatible with iOS5, or if it will be an unused feature until iOS6 is released.