iMessage, Notes, and Reminders in iOS and Mountain Lion

Hello Apple Core,

I currently have a MBPr and I am a previous owner of an iPhone 4. I am due for an upgrade and having a tough time making my choice of phone and mobile OS. I am very intrigued by Mountian Lions synchronization of iMessage, Notes, and Reminders between the MBPr, the cloud, and an iPhone. How good of a feature is it? Do you use it often? Is it buggy? Is it an everyday must have feature or is it just something that is nice to have but hasn't really changed the way you use your devices. Thanks for the input guys!