Immediately after install, did not even update, I got into a console window (Ctrl Alt F2) and logged in as root. Did
# pacman -Rnsd --nodeps xfce4 xfce4-goodies
and totally nuked XFCE.
reboot
when lightdm came up, again got into a console window and
# pacman -Syu
Then I checked and make sure I had the intel-ucode and xf86-video-intel packages, which it did.
Next
# pacman -S gnome gnome-extra
When it prompts for which packages to install DO NOT install 7 (gdm) I go through and pick about 40 of the 67 or so packages and made sure 7 was not one of them.
Reboot log-in with lightdm. Worked like a charm. This way I pretty much eliminated XFCE before installing the new DE. Might be a little cleaner, maybe.
Thanks for everyone’s input on this thread. You made it easy.