Quoting Steve Litt (slitt@???):

> I have two reasons someone (not me, but somebody) would prefer to start
> up in a GUI:
>

> 1) Some members of my family consider it an immense challenge to have
>    to remember to input their username and password at the console,
>    recognize that they're logged in (as opposed to have fatfingered
>    their password and need to try again), and then type "startx".

>
> 2) Some people can't be trusted to type the command like this:
>

>    startx;exit

>

>    so that the a badguy who terminates the GUI doesn't have access to
>    their command prompt (although they could just access xterm within X
>    anyway).

Which as the legit user is _very_ easy to prevent: E.g., if disinclined
to type the aforementioned, create shell script /usr/local/bin/go that
does that, and use it instead after login (if you want to start X11).

> Personally, I always boot to CLI and startx to GUI.

'startx' (or equivalently 'xinit <name of wm executable>' or countless
other variations) really has no significant disadvantage or advantage
over a display manager, per se, except tying up a VT while X11 is running
- and I suppose you might be able to fix even that by backgrounding it.

It's mostly just a matter of local preference. And IMO a well-customised
display manager (certainly including xdm) looks neat.