I also have installation issues. I downloaded the installer, let it install on a new 16G SD. My RPI 3 started booting, but after the message 'Starting Kernel' it gave no more messages and restarted the whole boot process.
That was in the weekend. Now (tuesday) I retried. Dowloaded the installer again, but it was the same as before. Restarted the installer, but it does not give me a GUI anymore. I get these messages on the terminal:
QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/user/0/runtime-root'
libGL error: No matching fbConfigs or visuals found
libGL error: failed to load driver: swrast
Unrecognized OpenGL version
Unrecognized OpenGL version
Now, the installer hangs without further action.
In between, my Ubuntu Xenial had some updates installed, so that might be the cause of this last problem.