Hi there! I am just about to replace my 17" 2009 MBP, as it has an intermittent startup fault I just can't figure out. I use GarageBand a lot to record real instruments (anything up to about 15 tracks per song) and I found the 4gb of ram was holding me back. Will the 13" rMBP(lowest model) be a significant step up? I can't really afford to get it with 16gb of ram, so will have to stick with 8gb. I may also step up to logic at some point, how will it fare with that? Thanks!