I just upgraded to a SP 01 Accu-shadow from a Glock 17L for 3-gun. What a difference! Much more accurate and the weight difference is a bonus, transitioning between targets is not a problem and so far the gun has been flawless using handloads. The biggest problem I have and I believe detracts from CZ in 3 gun is the lack of aftermarket support and the availability. Holster selection sucks and figuring out magazine extensions can be confusing. So far, very happy I switched. As for the cost between a STI and a CZ, $1450 for the CZ and approx. $2000 to buy the STI plus another $500 to actually get it to run right (that from several STI shooters I know).