A word of caution on the CZ kadet kit. I put the kadet II kit on an sp-01 and had tons of failures to feed and eject. Both the kit and the sp-01 were brand new so I sent them in under warranty to wolverine. OVER 14 MONTHS LATER they still didn't have the parts from CZ (extractor spring and extractor). Wolverine eventually stepped up and offered me the sp-01 specific kit, rather than the kadet II kit, taking the hit themselves. I tried holding out on the parts as there weren't many reviews on the sp-01 specific kit but at the 14 month point I caved and had wolverine install and send me the sp-01. Just arrived last week.
I own many CZ guns, all shoot great, this was my first issue. I was fine with that, life isn't perfect, but when you can't get simple parts under warranty...after 14 months! Then I start second guessing my purchases. So just a word of caution, great guns, horrible support.
For clarity, wolverine was great, CZ dropped the ball and if it wasn't for wolverine finding me an alternate solution I'd still be waiting on a simple parts replacement.