Some of you know, that I had excessive stacking and a rough trigger to start with on my P07. I had polished and dry fired the snot out of the gun and put several hundred rounds through it, but still wasn't happy.
Sent it in. ONE week turn. Polished (and I think replaced) the trigger bar, replaced the hammer, disconnector, and polished the bearing. It is much improved, and quite suitable for serious use.
Good on CZ USA. MUCH improved CS over 10+ years ago.
BL: If you really have a problem, send it in rather than replace all manner of springs and things.