Regarding the mag release button and being extremely hard to depress on a full mag, Ive discovered pretty much all of my guns are more difficult to depress if the mag is stuffed to capacity. Ive got a XDM 5.25 that has been my main gun for many years before I ever got a CZ, probably has had 100 billion rounds fired through it, and when it has a full mag of 19 rounds inserted is still almost impossible to drop without putting a little upward pressure on the mag. So this is not totally a CZ thing, and I only realized this after I started messing with my P-10C and doing some comparisons since dropping a full mag doesn't come up very often, at least for me. The XDM is also ambi with buttons on both sides of the grip so perhaps that design is going to be inherently this way, at least to some degree.