Depends on your budget. Can you afford to spend $1000's on the high end programs just to find out the learning curve is very steep and not exactly what you want (of course there are demo versions for most? If you want to learn modeling there are several free modeling programs on the web (Anim8or, Blender, Milkshape ,etc) that give you the basics and have OK render engines. Though Bryce isn't a modeler with patience, practice and work you can acheive some great things. Of big note Bryce can import many formats but cannot export any native models except for terrains, rocks, lattices or meshes imported from other programs.