Hi, this is the first time I write a message. I'm planning to get a new MBP, now, I have a HP with W7 64-Bit and it just DOESN'T WORK WITH RECORDING PROGRAMS. I'm a little tight on budget and I'd like to know if I'll get a lot of difference while using the laptop for recording (Ableton Live, Reason, Pro Tools, etc) between the high 13" model (dualcore i7 2.7GHz) and the low 15" (Quadcore i7 2.0 GHz). The effort of getting the extra 300$ is really really big, so I'll be very thankful if anyone who knows about the subject could help me. Sorry for my English Thank you.