Another comparison between Cycles, YafaRay and Blender Internal render
Here is another study comparing the results of a render made with Blender Internal, Blender Cycles and YafaRay using an architectural scene as a basis. A few years ago there were very little options to choose in terms of external render engines for Blender, and today we can`t complaint about having options. You can choose from Cycles, YafaRay, LuxRender, Indigo and even V-Ray. This new study comparing the results for all three renders can be found in this thread at the YafaRay user forums and was created by an artist called rio.