Carrara has a great renderer. It is fast (ridiculously fast even on my old pc) and easy to use. All of the great things people have said here are true and the render engine is capable of results that you only see in the big boy apps. On the downside I would say that it can be a bit odd when confronted with some of the more difficult tasks. I find area lighting to be quite difficult as artifacts are generated with very high settings and using objects as light sources can get slow. (Mabey it is the renderer I I have to learn to use it better) Overally I really like it and with some tweeks it will be perfect.