Now I'm referring to LightDM display manager...
yeah that's the reason why the current gdm with gnome3 couldn't do "Automatic-Login" as far as I know why...OMG! X(
so I've decided to move to LightDM. and loved it.
Is there any weakness? yeah a few. the LightDM is wasting time to boot especially the part from X kicked to session loaded. yep that's terrible thing exactly slower than GDM.
you guys already had experienced? ;)