Ask HN: Which Mac Book should I get

So I'm looking to replace both my vintage laptop and my aging desktop with a Mac Book. But I can't decide between the 13" Air or the 13" Pro. My main use will be web development, I was leaning towards the Air as I'm planning to do some extended travelling next year. The problem I can foresee with the Air is that I also write and record music, and my current laptop is a dual core 1.6Ghz with 1Gb ram, and it will often struggle when recording. At 1.7Ghz dual core the Air is not much faster. So to cut a long, rambling question short: Does anyone have experience using music software (specifically Cubase) on a Mac Book Air? Will the fact that it's an i5 and has 4GB make it cope much better than my old Centrino with 1GB? Thanks in advance.