I know this thread was made like two years ago but I'd like to build the silver sp2009 it looks so cool. Did you have to use a high flow valve to get it to cycle? I was thinking about using my glock 19 strengthened recoil spring if it fits but I heard that the hammer spring is too weak for a metal slide let along an enhanced recoil spring.

The high flow valve certainly helps it cycle better. If you could modify an existing recoil spring to fit that would definitely help because the slide return is a tad sluggish. Too bad you can't install a better hammer spring in it. It's a slow performer over all of a gun, but it sure does look pretty!