I feel the same way - lighter, unencumbered. I left Facebook almost a year ago and haven't been back. My main reason was privacy concerns, but I also felt empty after checking it many times a day. It was a great decision, and more people in my social circle have left since.
There were many things I've said to people through Facebook that I actually wouldn't like to have data-mined (no matter who's doing it, Facebook, AdAgencyX, or the NSA).
While my Google searches, email, and other "free" services are still used in a similar capacity - I'm also working to switch off of those.
Leaving Facebook has been the best thing I've done so far. I feel lighter and less heavy with the urge to check it ALL the time.