I think personally that the preview renders have a freshness all of their own and also it's the speed.
Pity their render wasn't as good as Max. I use both and I find it a pain as I usually build the same models in each program for different reasons.

Max for adjusting vertices and renders and poser for speech, expression, model manipulation, clothing and all Daz has to offer.
I wish there was a program that encompassed all of these........You don't know of one do you?

Cheers  billythekid