I would never want a pistol with a completely different mag release for anything more than a target pistol. I've trained for so many years with the standard push button mag release I know that is what I would revert back to during stress. That rules this one out immediately as a defensive pistol, regardless of how good a pistol it is.
That's too bad for you, since the HK/Walther-style paddle release is superior in almost every respect, and is easy to adapt to with an afternoon of shooting.
Walther caused such an uproar when they switched to the button release in the PPQM2 that they have re-introduced the PPQ "Classic" to the US market for 2014.