Which of their models are you working on? (I might already have it rigged in Bryce for you ;) ) Yeah, it takes some time, but working your way through mesh-by-mesh can be worth the effort. (Esp. with those models) The big thing to remember is that the images are just part of the texture. Don't forget to work in some Bryce procedurals to add grunge and variety to the images and work out bump/specularity and reflections as well. Just as an example, the background of the attached image is Sean Kennedy's Falcon Cockpit model from the site you mentioned. The character was composited in with a video editor and the control panel's diffuse map came with the model. Everthing else, though, is all Bryce lighting, smoothing, procedure texturing and rendering. Turned out a lot better than the default "biult-this-with-card-board" look that a basic import produced. Have fun!