That does not appear to work for me. I have a 144hz screen (and yes, I just checked to make sure, it's properly running at 144fps for other applications) and with this I'm still getting a 60fps lock. Only setting "this.TargetElapsedTime = TimeSpan.FromMilliseconds(1000f / 144);" in the main game class works, but that would be a hardcoded limit.
Edit: Setting SynchronizeWithVerticalRetrace = false and PresentInterval.Immediate doesn't work either, even though the documentation says "There is no limit for framerate."
Edit #2: Resolved, I was running borderless window mode all along and my GSYNC wasn't set to be enabled in windowed mode aswell (think I had some issues previously playing games in borderless window with other stuff on 2nd regular 60hz screen caused stuttering on that one, will see if it works with new drivers now)
On a different note: Am I correct that MSAA is still unsupported on Windows platforms for now? Looks like it has been moved to 3.6+ milestones.