When comparing GDM vs LXDM, the Slant community recommends GDM for most people. In the question“What is the best Linux Display Manager?” GDM is ranked 8th while LXDM is ranked 9th. The most important reason people chose GDM is:
GDM is dull, but it just works, and it is highly stable. It's easy to switch between environments, and it integrates really well with Fedora or other Gnome Distros.
Ranked in these QuestionsQuestion Ranking
Pros
Pro It just works
GDM is dull, but it just works, and it is highly stable. It's easy to switch between environments, and it integrates really well with Fedora or other Gnome Distros.
Pro Can run Wayland sessions
GDM can start Wayland sessions, which is the default for recent GNOME versions.
Pro Always signs the GNOME keyring
Works with any desktop. SOome display managers such as SDDM don't open the GNOME keyring at login.
Pro Not so difficult to customize
You just have to know which files to edit, and you can do quite a lot.
Pro Fast and fluent
Pro Works with Nvidia
Works well with Nvidia.
Pro Only two dependencies
Only needs GTK and Xorg-Server.
Pro GTK2 and GTK3 versions
Pro Works well on USB
A full install of arch on live USB works well on many computers with no text issues with LXDM.
Cons
Con Tied to Gnome
You basically have to use Gnome or one of its forks to use it properly.
Con Really hard to customize
You'll have to recompile Gnome's resource files in order just to change the login background.
Con Depends on GTK and its dependencies
Con Ugly UI
It is very simple, and you can't change the layout.
Con Bloated
As with anything Gnome, there's a level of inelegance to be expected when it comes to absolute performance. It's supposed to be a login manager, not something bespoke.
Con Requires Xorg-server
Currently LXDM does not support wayland.
Con Depends on GTK and its dependencies
