Hi everyone, I'm a graduate student in physics and am looking towards purchasing a Macbook Air or Macbook Pro (13") as my primary computer. *Most* of what I do is relatively low-key (web, coding, playing with photoshop/illustrator), however I will need to occasionally run Mathematica/Matlab/numerical codes. I'm leaning towards the MBA because portability is important and it is comparable in performance to one of the current 13" MBPs if I go for the 2.2 GHz processor and up 4 gigs of RAM. I know that for most applications RAM is the limiting factor, but my question is this: for Mathematica/Matlab/number crunching (some of my longer codes can take several hours on my current 2.4 GHz macbook), will the difference in processor speed significantly affect my computation time? (And will it cause the MBA to run warmer, as it has for my current macbook?) Thanks for your input! Flip PS -- Like many others who are thinking of buying a laptop, I'm also weighing the MBA "right now" versus waiting to see what the MBP upgrades are like later this year.