I have been playing with Solid Angle's Arnold renderer and I can honestly say it is the best experience I have had with CG rendering. It is simple in it's settings approach in that it grounds you to a sample count in only 4 areas, AA, Glossy, Refraction and Diffuse. In short it means there is a LOT LESS time spent wasting time trying to find the magical render time saver leaving you with tons of time to spend just making a beautiful image. The image below has about 5 hours of work put into it and took 10 minutes to render out a few color passes and an AO.
