I don't listen to those who say that the button can be pressed accidentally. It takes a deliberate push to activate the decocking mechanism. It is only an issue if you want it to be.
I handled mine just now, and again, there is no way that button will get pushed in regular or "aggressive" handling-if there is such a thing. Anything being possible, the button could be pressed if dropped on top of an object that presses the button, but that is a "chance" I'll risk.
Also, if you do press the decocker, it just takes a short "chamber check" of the slide to re-cock it. I saw but never handled the Gen 2 version, but I like that it has an adjustable front sight. If it still has the fantastic trigger, it is hard to beat, especially for the price.
AND, if you aren't convinced about the button, go for the TP-9SF which is minus the button.
Lastly, due to the failed coup attempt there in Turkey as well as other things I don't agree with, I'm now looking elsewhere.