The UI has always rubbed me the wrong way, which I haven't really quantified. Not "wtf, no gradients? fail", but just a preponderance of small things like weird defaults, chunks of menus / screens that are inconsistent with the rest of the application (so you end up checking 10 places for a simple thing), and minor inconsistencies with other applications that I keep re-discovering after using it for a few months that I have to go back and fix.
