I have only used ubuntu (with unit and gnome as DE). I have heard people saying that ubuntu are for beginners and advanced users use fedora, open suse or arch. But all the difference i have seen is that the desktop environments are different and the package managers are different(ubuntu using apt, fedora using yum and arch using packman).
so my question is how are these distributions different if we fix the above lying DE(which interacts with the user) to gnome? What is the actual difference apart from the desktop environment between different distributions of linux?