Stan's right, Carrara works with V4 and DAZ content just fine.

The various fixes for her joint bend issues work much better in Poser. And as far as I know, Poser doesn't have any problems with DAZ content. Most of what I use has come from DAZ. V4 can go in the Hair Room, she can wear dynamic clothes from the Cloth Room and she can wear clothes fit to her in the Fitting Room. I don't use it, but she may even be able to use the Face Room. Poser even comes with Wardrobe Wizard witch is also a big help in expanding V4s wardrobe.

Even Genesis will work in Poser (with DSON) although you can't put more than one or two dressed figures in a scene before it starts to slow things down.

I use both Carrara and Poser Pro (2012 and 2014) and quite often I begin a project in Poser that I find will work better in Carrara. I save the scene or the characters in Poser and open them right up in Carrara. With a little tweeking I'm ready to go.

Like I said before, it all depends on what you're ultimate goal is as to which software will be better for you.