Hey there; had some issues with the Rift where Rift owners had to play in VR whether they wanted to or not. They can now play in regular mode or VR mode as they see fit. (There might be a "Your headset isn't supported" message; ignore it.)
And the separation of church and state means that the Rift runs with forward rendering (which allows antialiasing) whereas it runs in deferred rendering for everyone else (which uses fxaa instead) ...
Bottom line, some performance improvement when you're not using a Rift.
Enjoy!