Red-5 said:
Tuning them is next to impossible. The only thing that can be improved at this time is the DA pull, at least according to David from CGW.
What's to tune?
And did he say, "the only thing that can be improved" or "the only thing that needs to be improved"?
Do you have one, or have you shot one?
The Sphinx is basically a CZ -- but a higher-quality CZ with a few design enhancements -- like interchangeable grips that make a difference (both wider and deeper/longer), and some simpler ways to do things (like changing hammer springs.)
Until David (or someone else) develops a trigger-pull length reduction kit or a short-reset trigger (harder to do with the CZ design, but possible), I don't know what else you'd want to tune. Most of us who have talked with or emailed David know he considers the Sphinx line to be high-quality guns.
David's Cajun Gun Works does offer a trigger tuning kit -- several springs -- that greatly reduces the DA pull, and lowers the SA pull a bit. But even in it's native (un-improved) condition, the trigger is smooth and the break crisp, just heavier than some like. (There is none of that CZ "hammer-camming" phenomenon.) He also offers a stainless steel guide rod, and a recoil spring, built to his specs. (As are all of his springs.)
I've got one of the CGW Sphinx SDP upgrade kits but still haven't installed it. (That's because I made the mistake of trading into about four guns recently, and my gun time is focused on the newest ones.) I did go to a lighter hammer spring on my SDP (using a CZ Compact 17 lb. hammer spring) some time back, and that made enough of an improvement that I've not felt pressed to install the CGW kit. (Others have gone to lighter CZ springs from Wolff with some success, some failures.) I will install the new springs, one of these days. (I keep hearing a voice saying, "if it ain't broke, don't fix it!)
I've also got an AlienGear holster for the CZ P-07, and it fits the SDP like it was made for it. WVSig found a holster, too.
There's not much else I need, right now, after getting and adjusting a couple of very good CANIK mags.