I bought a Sprinco recoil reducer for my CZ-100. This superlight .40 S&W pistol had a nasty bite to it even though it was quite accurate. I could maybe go 50 - 75 rounds with it before giving up. I put the recoil reducer in and it was a vast improvement in both accuracy and recoil. It tamed the beast very well.
HOWEVER, the gun would exhibit constant failures to feed. Sometimes it was as bad as every shot, sometimes every 5th shot. While it felt better to shoot with the reducer, it was completely unreliable. For SD, keep the parts stock. If you're just messing around at the range and your pistol is too unruly to shoot for long, a recoil reduer may help. But don't rely on it.
To be fair, Sprinco only made a couple of recoil reducers for this particular gun. I've heard lots of good things about the 1911 and HK versions. YMMV
