The ESR5 will make a better all around pipe and will even work well with the big bores. The Zeppelin pipe is for top*end and most wouldn't feel the benefit unless you have a drag motor.
I have this pipe, and love the way my stck cylinder 310 runs with it, but starting the MF is down right scary. I have a permanent dent in my shin from this thing. If you buy this pipe, i think it should come with a pull rope, and a buddy to pull start you!!!!