Stick to DSLRs or move to mirrorless?

I was at the same point this spring, and decided to go M43 (like you coming from a Nikon D80). After a long hesitation, I sold of my D80 and lenses, and bought the Oly OM-D. The jump in image quality was excellent; I now can do my 'casual party shots' at Iso 1600 and 3200 and am satisfied with the results. For serious work at lower ISO's the OM-D exceeds my needs; I can make my 12x16 inch prints and they look good enough for me. In fact, I found I can even crop quite a bit without visible drop in printed IQ (essential when working with primes, which I prefer).

Having said this, the OM-D requested quite a painful learning curve. I hate menu diving, but the OM-D -and most Oly's- are very flexible in set up, which needs lots of menu work,. And those many menus are a b*tch to find your way in. After 5 month, I still keep my (self)printed manual in the photobag, and whip it out regularly.

The good news is, once you have found a useful set up for you, you don't need to get into the menus while shooting. Once I have set up my camera for a certain situation, I usually can shoot without even using menu's.

In my case I usually shoot raw and work in P or M. There are two dials on to to shift exposure/aperture, and to correct over and underexposure, I have my ISO under the OK button, my WB under the Fn2 button, a smaller AF frame under my movie record button and a digital zoom under the Fn1 button. That last one is still under review; it comes in handy when using my minimal bag (just 12mm and 45 mm primes) but I am not yet sure the IQ loss is palatable in large prints. Once I have set up my camera for a certain situation, I usually can shoot without even using menu's.