I've been a professional UNIX & Linux Systems Admin/Engineer for about 10 years, using Linux as my sole home & business OS for that time.
I started with Debian in 1994 or 1995, then to Arch, Fedora, Red Hat/CentOS (I'm a RHCT & RHCSA), Fuduntu and now back to Debian via LMDE/MATE.
About the only thing I use a GUI for is a terminal manager, web browser/media player & file manager.
Since Linux administration is my "day job", the command line is usually my only option and I must know it well.
Trying to run a GUI over a 115200 baud (or slower!) SoL IPMI connection is not...viable.
I flirted with Gentoo and gave it up when it once took all weekend to "emerge world".
I do not like the way Ubuntu breaks upstream compatibility with Debian and this PPA thing is yet another annoyance.
I imagine I'll be re-installing LMDE before the weekend is over, but for now I'll play with LM15 some more.