I can only echo here what some others have said.

Like Rids I have both apps and use them for different things.  Same thing with Bryce, which I also have.  If I'm doing a landscape, nature scene, I'm going to do my best to work with Vue 5 I.  The ecosystem is second to none and really can't be beat in any other app in this general price range.  Obviously some of the more high end apps are going to be able to do more, but of the medium to low end apps, this ecosystem really rocks.

Now, also to second some others, demo them both and strongly consider your needs.   Yes, Vue is more tempermental than a pure bred cat living with a fashion model, but the landscapes you can get out of it are worth the frustration.  Carrara 5 Pro can import Poser files, including support for Dynamic Hair and cloth.  Are you going to be animating?  Carrara has a more stable interface that I've found so far, but a much different workflow.  I don't care for the three rooms of modeling, but it does render really nice images.

I also post at DAZ and there are a few threads going in the commons forum.  If you also belong to DAZ and have joined the Platinum Club or are considering it, Hexagon 2 is $1.99 right now for PC members and I know that is a modeling app.  So, again, base your decision on your needs and which app feel right for you when you demo it.