I opted for a 10" puller rather than a 12" pusher. By eliminating the mechanical fan I freed up some HP (maybe not much, but every little bit helps). I considered the pusher, but when I looked at how much it was going to disrupt the air flow I decided that a puller would be better. It seems to be working great. My car runs at 180-185 at speed and never gets above 190ish after coming to a stop after a hard run.
Maybe a pusher would do just as well for my car, but so much of the advice I read was in favor of the puller that I couldn't simply ignore it.