I'm with Rex on everything above. Creating good looking models is all fine and dandy, but as Petr stated as more of the larger poly models get added, it is gonna hit the resources of the machine harder. There's no need to have detail that is not neccessary to the output of the beam of the profiles, the body parts of the fixture should definitely be proportionate to each other and replicate the fixture the best it can to an extent, but unless you're doing rendering's, once the scene goes dark for programming, the need is not there. We build all of our models from scratch in C4D and have been able to severely lose poly's and vertices without degrading the "profile" of the fixtue body parts. If everything is built correctly, one should be able to handle over 1000 fixtures and a full scenic model build out without too much FPS loss pending hardware.