I've been using SMEserver in my home network since 2006 and in my workplace since 2008.
My *native* environment are MS Windows since 1996 (Win 3.11).
But since late 2008 I've moved over to Ubuntu desktop Linux (at home) with great satisfaction.
What really pushed me in this direction are the release of Windows Vista, with all it's activation, validation and DRM-stuff that's restricts usage and compromise integrity.
I've released some additional info about SMEserver on my site: http://bends.se
One good thing about Linux are the many HowTo's, but there aren't enough.
And many of the existing ones are not detailed enough for someone with my (current) Linux experience level.
It takes a lot of searching and reading just to install a simple program.
But I'm not only complaining, I am contributing with some of those silly HowTo's.