Hi Bob
If I may respond and correct, I think you have your runlevels indicated here incorrect, even if you take the disparity of SOME Unix/Linux distros. The traditional runlevel 2 is multiple users, no NFS (network filesystem) and rarely used. Your indicated runlevel 3 for GUI is also not correct, runlevel 3 is multiple users, command line (i.e., all-text mode) interface and is the standard runlevel for most Linux-based server hardware, no GUI. The runlevel for GUI is runlevel 5 for multiple users, GUI (graphical user interface) and the standard runlevel for most Linux-based desktop systems.
Also incorrect with Debian and Ubuntu, yes they are not 100% compliant with UNIX and Linux standards, but they still use the runlevels, here is a post covering this in more detail for Ubuntu and how editing the lightDM config file resolves this, for those interested. http://askubuntu.com/questions/228402/boot-to-runlevel-3
Regards
I shouldn't have said they don't matter at all. Of course 0,1 and 6 are well defined.
I've installed dozens of systems from scratch, though most of them have been upgraded from older versions. Never have seen runlevel 5.
Only have seen runlevel 3 on centos, an old Vanilla SVR4 system and AIX.
Here for example, is my old ubuntu bottle (booting into full GUI w/ Unity):
bob@ubuntu-vbox:~$ cat /etc/issue
Ubuntu 11.10 \n \l
bob@ubuntu-vbox:~$ runlevel
N 2
bob@ubuntu-vbox:~$ uname -a
Linux ubuntu-vbox 3.0.0-19-generic #33-Ubuntu SMP Thu Apr 19 19:05:57 UTC 2012 i686 i686 i386 GNU/Linux
Anyway, that's not the issue. The issue for MC is whether or not a GUI is needed and using runlevel as shorthand for that is not useful IMO.