Needed some tweaking of the cockpit and decided after 5 years of using a riser bar to go back to a flat. While I was at it, I went ahead and bought into the hype and got a 31.8 setup.
I have to say, the flat bar is great. It's a little wider at 620mm and gets the job done. Steering feels more direct and accurate -- the bike rails and is much more precise in picking lines. I'm really starting to understand this steel thing -- There is a definite compliance to the frame and when the trails gets really flowy, this bike just sings. Rode twenty miles of rooty singletrack and didn't once miss my fully.
As for 31.8 -- I don't feel a damn bit of difference in stiffness. Maybe I'm dense, but I'm calling the standard a bunch of hype. That said -- it looks really sweet, so I don't really mind. I'm a sucker, I know.