I'm finally taking the plunge and learing how to render in 3delight. I'm choosing 3delight over Prman primarly because it's cheaper ( and the first license is free). I also like the intergration better.
Pixar's artist tools are a bit too artist friendly for me. Every time I have messed around with them I seem to get more confused about what's going on. They tend to hide things and make things work without me understanding how they work. In my book thats a big no no. Becasue if something doesnt work I need to make it work.
They also have a shave and a hair cut workflow that I'm interested in. Hair, fur and grass are all things I would like to be able to render better and unfourtantly raytracers are not able to do those effects quickly.
It also allows me to use python in maya. Python is everywhere except for my main 3d package at work (3d max) so I'm going to be able to test the waters with out having to install and cobble together the blur python package for max, that I could never get to work at home. But that was just my experience.