I recently tried out Blender with it's cycles rendering engine. I must say I am really happy with the final results. Especially if you think Blender is free software and I'm getting way more realistic final results in my opinion. The UI in Blender is kinda horrible, especially for new people... it's way harder to learn your way around compared to C4D.
Anyway here are some pictures:
This is an interior test from a tutorial I followed and then added some of my own touches to it. (I didn't model the furniture)
This is an exterior test. I modeled everything apart from the trees, grass clumps and scrubs and a few other tiny details. I modeled the whole house in Blender though.