I've found this to be true, as well. In my case, green is the weakest color and blue is the strongest, so pushing the 445 through a mirror and 2 dichros isn't an issue since there's more than enough headroom on an m140. Red is the next most plentiful color, and I've got about 100mW to spare there, so again if there's a bit of loss I just crank the power. Green is last because I've been having the most trouble getting enough power out of the PL520. When I switch to a PL520-B1 it should eliminate the issue of not enough green, but for now Bl->R->Gr->Output is working quite well. Also, the projector sleds are cheap and have dichros that work fairly well in this order.