I actually think NM tries to do far too much.
I don't seen any advantage in software that deals with WiFi
and ethernet together.
I do.
It is very useful to have something that automatically switches between
ethernet and wireless networks transparently depending on what is
available and what isn't. NM does this for you and presumably it can
only do this by knowing about ethernet and wireless at the same time.
I'm one of the lucky ones for which it worked (currently between laptops
after my last one died :( ) flawlessly. If only wireless was available
it would connect to that, if ethernet only that was used. If both, if
would favour ethernet over wireless, unless specifically told not to.
Very nice.
I agree though NM is not yet ready to replace the older tools
completely, since it doesn't work for everyone, but I think it is more
than ready to become the recommended default (it already really).
cheers Chris