well, for me the main draw of using xcode would be code folding - it's a way to visually simplify the editor view by collapsing sections of code, so the user can easily/quickly scroll through multiple functions without being distracted by their contents. It makes editing complex sketches much simpler.
fyi - the link to the xcode template on that wiki page is broken & the version on the author's blog doesn't seem to work with Arduino 17 (even after implementing changes mentioned in the comments) - http://robertcarlsen.net/2009/02/28/using-arduino-in-xcode-532