Sensor size (full frame or crop) is a matter of preference for SLRs now. Nikon does a pro crop sensor camera, even. The biggest improvements in the last few ye

Sensor size (full frame or crop) is a matter of preference for SLRs now. Nikon does a pro crop sensor camera, even. The biggest improvements in the last few years have been in dynamic range and being able to take photos in darker and darker scenes. I think the easiest win now is getting top-quality (not necessarily new) lenses. Newer lenses can be worse in some ways. They've generally traded build and image quality for the convienience of auto-focus and zooming.