My 4GB MacBook Air 11" is slow with Parallels, postgres, apache, emacs and the usual programs (mail, chat, multiple browsers etc.) -but usuable. Even my 3-4 ye

My 4GB MacBook Air 11" is slow with Parallels, postgres, apache, emacs and the usual programs (mail, chat, multiple browsers etc.) -but usuable. Even my 3-4 years old MacBook Pro with 8GB was a little slow, but processor speed was the culprit. My year old MacBook Pro (2,4 i7) with 16GB is fast, but I have more memory then I actually need... I've even used it with three simultaneous Parallels instances (FreeBSD Server, FreeBSD CI and Windows 7 client) and it runs fine. 8GB memory is not a dealbreaker for me, I'd buy the new MacBook any day :)