Just sold my MBP yesterday, and promptly picked up my MBA right afterwards. Super happy with it. I then noticed someone selling their MBA on craigslist ... 13" 1.86 i7, 256, for $1300. "Barely used" (the infamous line). Should I go for it and save $400 for a used machine with the faster chip? I don't "need" the i7, and opted for the i5 mostly to avoid heat/noise. I'm torn!