Replacement Camera

I have been thinking about upgrading my 40D (APS-C Sensor) for the last few years. I am always disappointed with the photos. I have invested in 2.8 F stop lenses and a flash years ago because i thought it was the ISO and the photos still turn out poor. Output is discouraging me from even using it now, so i have to get something better. This camera has treated me well, but now im going to upgrade to a full frame camera with better ISO.

Budget
This is a tough question and plays a...

Replacement Camera Replacement Camera