You're right, the obj does work better.  I'm not sure what you're referring to when you ask " . . . why would you need materials to finish the modelling process?"  By way of explanation I might, for instance, make a flat sail, export it, then use Amapi, Rhino, or LightWave to give it the right bend and sag. Then I could import it back in the shape I want before applying materials and grouping it with a yardarm & mast, etc. Ok, that's not a very good example, but do you see what I'm getting at?

 I like Bryce; it's familiar and intuitive and I'd rather stick with it than become a convert to LW or Carrara (though I often envy their render times).

"Imagination is more important than knowledge." - Albert Einstein