I'm in the market for a new rig. I primarily use my Macbook Pro for application (java) development professionally and photo editing as a hobby using Aperture . My current machine is a 2.53 Core 2 Duo with 4GB. Aperture is a little slow but manageable. I'm thinking about moving to a Air -- 1.8 GHz dual-core Intel Core i5 with 4GB memory. So what is faster? the 2.53 Duo or the 1.7 i5? I have a 22" external monitor so screen size is not really an issue, I just like the extra portability of the the Air.