And then you have apps like mine which Ctrl+o will either toggle between forced portrait/landscape mode or enable/disable auto-rotation, depending on the app.

More of a matter for CSSU but I tend to favor locked orientations because apps optimize for the new orientation or even do automatic reflow, slowing down rotations even more (fennec being the worst for me but even my own apps are annoying). This was brought up before (mailing list? bmo?) but it was decided it was a dev's responsibility. I did a first crack at it in my app but ran into problems. It'd be nice if there was a way for apps in the background to not get new window/desktop dimensions until they are activated (which could cause a rotation back so no reflow should be seen)