Probably the part where it usually can't find your JDK (and barfs with some random error on startup as a result) until you edit a config file or set some environment variable(s). NetBeans on the other hand usually finds 5 different JDKs on your system and asks which one you would like to use.
Actually, please start. I install the JDK via an installer, unzip Eclipse, run eclipse.exe, and it just works. Am I missing something?