joowon49,
"and a tricked out impulse will almost always out shoot a tricked out cocker. "
Dude, I presume you have never shot an E-Blade? Fastest thing I have shot. And you can upgrade a stock with the E-Blade without any other major alterations to ram, sledge etc.
Personally I would choose an Impy because they are easy to strip and fix. I don't understand timing on cockers. What can I say.