For me flexibility. I can figure it out and hack n learn if the results are going to be worth it for me. RuntimeDNA has a wall construction set room product that has a prebuilt room and u can turn off or add to or do your own thing, I like this approach. I don't like to have prop XYZ be noticed if I can flexibly change it around to be my own creation, that is a big plus for me ("oh you used XYZ product in that render huh?", ick!). That's me. The biggy for me is when there are lots of props and all the files are all over and I have to go and move the folders/files change it up. PLEASE make it easy on the harddrive directory and as flexible as possible. my 2 cents. Sounds interesting, I'll be looking forward to seeing the results when finished.