I've also gone from a 15" MacBook Pro to a 13" MacBook Air, and I'm thoroughly impressed. I still keep a Mac mini around as my house media server that holds the bulk of my content.

And with no “breathing” light to wait for when you close the lid, you never know when it has gone to sleep. Which means, that for all intents and purposes, you don’t think about the MacBook Air going to sleep. You are either using it or not. Like the iPad.

This was one of the things I missed when I first closed the lid on the Air. After getting used to Lion's Resume feature however, "sleep" is meaningless. You can restart a MacBook Air and have all your apps reopened and ready to use in less than 30 seconds.