I've got a chance to buy a 2010 MacBook Air a1369 model for cheap ($400) and gwanted to know about it. I know in the past, the Air had pretty crummy battery life, and they've imprived that in recent years. Are there any real glitches or problems with this model, that I need to be aware of? I'm on a strict budget, but even at $400, I don't want something thats not worth that. Thanks!