Quite a lot of people reported startup issues with the current iso because of GDM.
There are appearently driver issues in the current GDM which are not caused by our configuration (more here for example)
It would be nice if someone who was affected can test this build for us
GDM was replaced by lightdm which appearently fixes the issue (also the need for tty-switching which I personally experienced as well).
Its of course not a proper fix but still better than boot issues imo. If it works lightdm will be featured until a fix is available.