Simple question. There's a price difference between a grade A and a grade B of $75. I've read that the grade is determined more by the internals of the gun as opposed to the aesthetics. Would anyone have a second thought about buying a grade B? I guess my question is what exactly would HK see inside a grade B that keeps it from becoming a grade A? Is it more likely to malfunction or break sooner than a grade A? Any insight on this would be welcome, as well as some advice as to which I should go for. Thanks and sorry for another P7 question... there's been a ton lately.