Hello. Just about to get a 17" i7 for music production at home/live stuff/mobile recording, plus being my main computer for my main daily life! I'm gonna get an MCE optibay for 2 HDDs as 500gb is too small! So, I have a few options... For the multitrack audio and samples I'll use a 7200rpm 500gb. Then should I use another 500gb 7200rpm for system/apps/mp3s/photos/etc, or get a bigger 750gb 5400rpm for the extra space? How much of a general performance hit would I take? Can I fit a 12.5mm 1tb 5400rpm in the 17" (if it's not stupidly expensive) instead too for system/etc? I'm used to using a desktop with 7200rpms, so I don't want an expensive but sluggish £2k computer, but I'm also used to being able to stuff multiple big cheap drives in it too!