The Sony NEX-6, in my opinion, has the best balance between price, performance, and usability. It's very comfortable to hold, has most of the controls accessible without going into the menu, an excellent viewfinder, and most important of all, exceptionally good image quality. While I struggled with the Pancolar 50mm f2 on the 5D Mark II, it is a breeze using it on the NEX-6. If there is a full frame equivalent of the NEX-6 at affordable price, the world (OK, at least me) will rejoice.
Downtown Buildings - Sony NEX-6 & Carl Zeiss Jena Pancolar 50mm f2 @ f8.