Going Backside is a more natural way of surfing. Keep it simple - After hopping onto the board just lean your backend into the wave and feel the wave thru your feet. Once you get a good feel for it then you can start manuevering better. And most of all trust your instincts more going backside because your sight is hindered with your back is to the wave.
I can get more power on a backside snap off the top, cause you're going from heel to toe, and you can add more leverage with your ankle and foot. As for pumping, you can't do it the same way both sides. It's ergonomically impossible.. all your joints a facing the wrong way. I find the best way to pump backside is to point my toes more toward the nose, and turn my hips more perpendicular to the stringer. I seem to be able to pump faster, and pumping out of sync with the natural flex of the board just does not generate speed effectively. When it comes to pumping, timing is everything!
I've always wondered why it has been so much easier to do backside snaps than frontside when i can get so much more speed and do everything else better frontside. I like this scientific explanation