I only know what I use, I have the Keyshot bridge for Zbrush 4, Modo 902 and Vue 9, I get good results from them all, Keyshot and Modo are the fastest, Vue 9 is slow but I like it a lot. I also like the rendering engines in Poser (Firefly) and Bryce . Bryce is another one that can take a long time to render a scene.