Comment 6 for bug 806559

For my point of view getting a working system after upgrade is more important than choose a display manager!

As you can see in https://bugs.launchpad.net/ubuntu/+source/nvidia-settings/+bug/840462 , the debconf question - where i chose lightdm - left me with an unusable system (infinite loop of xserver when logging in.).

Switching back to gdm (which to found out took me hours) brought back the system.