I have the Z3 4-12x50 with the BT. It's outstanding in low light if you have the heavy plex reticle. My Steiner Gs3 3-15x50 is brighter, but the reticle is a tad too thin for very low light.

Man is condemned to be free; because once thrown into the world, he is responsible for everything he does. It is up to you to give life a meaning. ~ Jean-Paul Sartre