I use Daz | Studio Pro (free for a limited time! Get it now!) for my 3D reference images. It is my inspiration and my studio almost as much as my physical one. Daz Studio uses the 3Delight render engine which is fine. It’s worked really well for me and will continue to do so. It’s fast and effective.
The difference, however, is approximation.
Rendering through 3Delight you use shaders to approximate how materials such as glass and metal look. You use preset maps or ray tracing to approximate shadows and reflections. This is why it’s so fast. In a nutshell it guesstimates how things should look.
Enter physics based renderers. Lux is the one I use and Reality is what ports the information across to it. There is no guesstimating here- except on the part of the user. Lights are used as they are in photography, materials are calculated and the rate at which light passes through things or rebounds off them is determined through exhaustive scientific calculations. this is very processor intensive but in the end it creates the best real-world settings for your 3D renders! I am still learning all I can about this amazing tool, but so far I am delighted with the results.