I don't have the current version, but I have the one designed for the original MacBook Air. It fit the older one slightly better but works with either. It's a snug fit, and it takes a little while to get used to it. The main thing is that getting the top part of the flap over the notebook takes a bit of work at first until the fibers are broken in a little.
That said, it's a good solution for protecting the MacBook Air inside another bag, such as the front pocket of a notebook case or the flap of a suitcase.
I didn't catch the "MacBook" in the title of your original post. I was thinking the sleeve for the 13" MacBook Air. That one is a tight fit. I don't have any experience with the one for the base MacBook.
Yeah, I peeped it out at the Apple Store, and I just think its too tight, especially since I want a sleeve that I can quickly pull the Air out of with much hassle.