Both Bryce and Vue have demo versions. At least I hope the Bryce demo is still on Corel's site. Corel is no longer supporting Bryce, so I would tend to lean toward Vue. I have both and Vue is really nice and easy to learn. If you can afford it, go with VuePro. It has a really neat feature that if you import a pz3 file into Pro, go back and adjust things in Poser, the next time you open up Vue, it tells you that the pz3 has changed and do you want to update. Say yes, and bang - new pose in imported. Importing Poser itmes into Bryce is not as easy, but once you get the hang of it, it works fine.

LVS - Where Learning is Fun!  
http://www.lvsonline.com/index.html