I don't know about more refined, but it lowers the O.P. considerably. Your sweet spot with the new internals and valve should not nead to go above 180 psi. I have mine sweet spotted at 175 psi, IVG two turns in from flush, +/-
2 at 285 fps. Although much smoother, I had trouble getting the fps up with the checkit bolt, so I am using the TechT hush bolt.
This gun shoots like butter, lighter pump stroke, vary smooth and Quiet, WOW! I also took out the little bumper in the pump handle behind the return spring which helps feeding the auto trigger big time, less short strokes.
In my opinion, the Checkit upgrade kit makes a big difference and is vary reasonably priced.I got the polished stainless trigger too, the stock is way ugly! From what I understand Checkit is working on a new pump handle too.