Ok, after a few months with the MBA, this is my honest evaluation. The MBA is unuseable as a laptop! Just too many instances where the Core shuts down or the MBA just slows down to a crawl. Most of this happens when I'm just surfing the web, answering emails on Entourage and maybe editing a word document. Also, connected via a USB modem if that makes any difference. The MBA would just slow to a crawl about 80% of the time. I can really make it slow down to a halt when connecting to a external monitor as well. I go on business trips 2-3 weeks at a time. With this kind of use, the MBA just doesn't work. Its great for taking notes in meetings...but that's about it. I am seriously considering selling this and going back to my MBP despite the weight differences.