iLife
It is understandable that carrying an advanced featureset and lots of media manipulations can’t be all that speedy, but we’re talking about the interface responsiveness here. I am, trying to assemble my first home-made movie in iMovie, using a semi-modern Mac (dual-Ghz), don’t like clicking into a movie fragment and waiting for half a second for the system to understand I clicked in and update the UI. I don’t like browsing through the iPhoto library with an ocassional coffee breaks every time i click on an up arrow because my library contains about 600 photos.