Just got my MacBook Air Apple refurbed 11" 2011 base model about a week and a few days ago. I'm beyond pleased. It's been my favorite Mac so far and it is the ONLY Mac I have ever had (besides my Mac Mini) that arrived with ZERO issues. No marks, scratches, crooked hinges, loose bottoms, dead pixels, dust under the screen, nothing - absolutely PERFECT.
My only fear is that it being so incredibly small and thin and light I will destroy it like I did my iPad (smashed it into the wall corner by accident). I don't want a hard case on it since that's what I had on my iPad when it STILL got destroyed, so I am buying a Thule Gauntlet sleeve. Just hope I don't damage it while putting it in / pulling it out or while using it through some freak accident... which always seems to happen to me.
Anyway. I would highly suggest Apple refurb units for anyone considering an MBA purchase.