The thing I've always hated about eggs is that invariably something that uses an egg won't have the permissions to write to the default egg cache. It has gotten to the point now that if I know something is going to install an egg, I just do setup.py build and copy the build folder into site-packages. It's just not worth the annoyance for what is, at least as far as I can tell, no gain.

(Edit: read cache)