I've been working with 3dviz 2005 and mental ray for the past 6 months. I've gotten to the point where I know what I am doing and I know how to get the scene rendered well with materials, lighting and all. But my problem is time. I have found that for myself that mental ray seems a bit time consuming. I've been looking at other posts to see what the opinions are about vray and mental ray and I haven't found too much. I found that there is a preference for vray over mental ray on a poll on this site, but I would like to hear some opinions about the production time of vray vs. mental ray, as well as the it's pros and cons, learning curve etc. I downloaded the free version and found it somewhat simple to navigate through.