I turned chaperone completely off

Not that you'd want to. But it was kind of interesting for a bit.

With SteamVR off, go into the SteamVR config file. There you have more control over R G B and alpha of the chaperone. You can set it to be completely invisible (including the floor bounds).

Too bad there are no settings for playing with anti-aliasing / super-sampling for users of fast 3D cards.