Yes, self illuminating materials will eat up your render time a lot. This is in part because each triangle in the mesh is acting as a single light. For that reason its very easy to get the number of lights up into the hundreds. One way to get around that is to create a single square that overlaps the mesh, and set that as your emitter. Another way that I did once was to hollow out the insides in wings. (Using bridge) and then place a very powerful omni light inside.
Looking good.
