But as others have stated, as you have access to all the giant repos, installing any other software than the elementary-oriented stuff instantly feels disjointed, as toolkits etc. don't match.
This isn't really a problem with Elementary OS itself, more the proliferation of toolkits available, but to pretend that it is a drop-in replacement for a Mac (with its unified Cocoa UI) isn't quite right. (Yes, I know you can run FLTK and X apps on Mac so it's ugly too).