So far I've tried Premiere and Lightworks for bigger edits and they've both worked very well - Premiere being a little heavier and less stable, Lightworks being a little less intuitive but very stable and fast. I just saw this post and decided to try Avid's Media Composer for the first time ever. I've recently switched to the Mac for work and I've been looking for a video editing software to commit to (Final Cut is also an option, but I haven't tried it yet). If anyone has any thoughts about these (and their performance on a MacBook Pro), I'd love to hear it!