I own two of the Surefire G2 lights, one in 80 lumen and the other in 120. I also have the Polytac. Both are nice lights but I generally keep the G2 lights in the living room for emergencies and carry the Polytac in the car for everyday travel. The Polytac is advertised at 130 lumen, pretty nice little light. I have noticed the Surefire lights usually give you more of a overall spill of light and the Streamlight has more of a throw. I like them both but ended up giving a Polytac to my wife to keep in the car and bought another one for myself. I like them because they are simple, bright, and pretty tough for all occasions.
Take care -