Using the regular gui isn't very good for vr. You have to mirror any gui to the other camera perfect or it looks terrible. Look for VRGUI on the ovr forums for a plugin that does this, but it's a scripted solution. It also kinda sucks because you can really only use the center third of the screen if you want it to be legible.
As a rule of thumb don't do screen space gui, or actually really anything other than postfx in screen space. It's been noted by Palmer a lot that stuff being stuck to your face is not a comfortable experience so it's mostly avoided. My own tests basically had me agreeing with that. If you haven't already, check out their best practices pdf.
Have you tried the new ugui in 4.6b? It's in world space, and should be much easier to use in vr applications. Plus it's super flexible.
