This new Macbook Air has me really excited and thinking about buying one. For the last few years, I've been using a HP 10" Netbook with a whopping 1 gig RAM, and it lags really bad when trying to play 720p video. Will the 11" MBA play 720p flawlessly? What about 1080p? Would I regret buying the 2gig version over the 4gig? I mostly am just a casual internet surfer. I don't play games on my laptop. Thanks for any tips. Sorry about the noob questions.