On the Samsung 550 (the only model my Best Buy had on the floor), didn't do any scientific testing but definitely in the 5-7hr range. It's noticeably thicker than a MBA, but not by much; and IMHO the 12" (matte!) size is the sweet spot on a laptop. Unsure on exact specs, but plenty fast enough. Keyboard and click pad are solid as well (best pad I've ever used outside of Apple). Provided you can work within it's niche, it's a great machine for $450. Was sad to have to take it back (not in a position to throw money around I don't absolutely have to).

So you bought it and then returned? Best Buy allows you to do this?