Originally I was torn between the MBP and MBA. But after many helpful posts on here I am 95% sure of getting the 13", 4GB ram, 128GB ssd model for $1399. However, I do have one last (hopefully last ) concern before I pull the trigger and buy one. I went back to Best Buy (again... the guy there thinks I'm nutso I'm sure, and he's probably right). But I noticed that the wired ram (the ram being used by the Os) was 400MB on the 13" MBA, but 600MB or so on the 13"MBP. I rebooted both machines and still the same. I don't understand things like this too well. Is the MBA OS stripped down or something? Or is there really a 200+MB difference due to Optical drive, etc...? In seeing the difference, I'm wondering if the MBA has any latency issues that the MBP may not have? Am I missing something in the realm of audio recording that others out there may have insight into? I do not plan to record voice or guitar or bass onto the MBA (rather use my iMac for that), BUT I will be editing the audio files that I recorded on the MBA and I will be using ezdrummer, and other soft synths/effects (IK Multimedia, Celemony, Native Instruments plugins, etc...). So does anyone else out there that owns one have any experience in what I'm looking to do? Does the audio sync up nicely? Any noticeable lag, etc...? I know that the MBA can handle tons of stereo audio files that were already recorded. I guess my main concern is syncing up ok? I know this sounds ridiculous, but after recently doing a quick video using photobooth on my iMac and the audio and video were not in sync (like at all), I am wondering about the MBA's ability to function without noticeable lag as a DAW in garageband or logic express 9. Oh, and how is the battery life using it as a DAW as well, getting the 7 hours? Ok, LOL, obviously have more than "one concern", but wanted to get all of the remaining thoughts in my head out there for those in the know. Thank you for any guidance that you can provide.