Best Mirrorless for under 300 used... I am looking for a mirrorless that I can mount my Nikon lenses on with an adapter as well as their own lenses. I am looking at the Samsung NX 300 with its great low light sensor, APS-C sensor, good image quality, small size, and decent used price. Any suggestions? Also how does the NX300 compare to the Panasonic GH3 and Nikon D7000?