As I explained in my previous post, I've been on the hunt for a new PHP IDE. During past searches for this type of tool, I've always taken a glance at NuSphere's PhpED and usually went away screaming rather quickly because of how clunky, ugly, and just plain annoying the interface was (keep reading, though, they fixed this!). My last look at PhpED was verison 5.2 quite some time ago -- it was a good improvement over previous PhpED versions, but it couldn't compete with the Eclipse-based options (at least in the terms that mattered to me).
Which brings me to an important note: what I look for in an IDE is probably not exactly what another coder will look for in an IDE. From what I've experienced, choice of tools for most coders is 50% features/capabilities and 90% preference (oh hai, math!). For me, here is a list of features that are important: