I use both Poser 7 and Vue 6 Pro Studio.
Vue has a better render engine IMO but, like any rendering application, can take a long time if you set up for realistic renders.
Bear in mind that you won't need as much quality in an animation as a still picure, especially if there's alot going on. Freeze frame any film and you'll notice the quality does not appear to be as good as when you're watching the moving picture.
The main advantage to animating figures in Poser are that you can more easily interact with all of the scenery. This does not matter if you import all of the interacting Poser objects into Vue. Also Vue does not always correctly render Poser materials so you may need to alter them.
If you're doing outdoor scenes then Vue would be a better option. The higher end versions allow moving vegitation which interact with forces such as wind. Excellent indoor renders are possible with Vue 6 but at a cost in render time. I understand that Vue 7 now has native settings for indoor renders so this may spped things up but I couldn't say as I don't have Vue 7.