Laurie, you can do things with Sculptris, whithout having any idea how to model. It's like working with clay. Sculptris adds polys as needed, so the mesh you get will likely have some 100k of polys, even for something simple. Yes, you can render that in Poser, but you cannot rig it and you cannot use it as conformer. Marvelous Designer produces triangle meshes which behave great in the cloth room, but aren't good to conform. If you want to use them as conformer, you will have to retopo them.

You don't need any modeling experience to get something out of these programs.

A ship in port is safe; but that is not what ships are built for.
Sail out to sea and do new things.
-"Amazing Grace" Hopper

Avatar image of me done by Chidori.