However, there are times when spending the extra effort to add nice textures and lights outweigh the time it takes to post process in photoshop. I will most often do the bare minimum, to get my rendering times down, then put more effort in post processing.
However, as you fine tune the rendering settings, add more lights, soften the shadows, give the material textures and bumpmaps, you will quickly find out that the rendering times exponentially grow. If used correctly, Kerkythea can be quick.