One of the big resource issues with using the Poser shader tree inside of Vue is the the Poser API is not multithreaded which causes Vue (or any program for that matter relying on the Poser API) to really bog down.  I've never been able to get decent results using the Poser shader tree inside of Vue but I've seen Fixer's and VinceBagnas images and they really are quite good, so it can be done.  

ahudson, why don't you post some screen shots so we can see what the problem is.