Have you tried playing with the different size grip inserts? On my 9/40 M&Ps I need the large one, but with my 45s I pulled to the left SHO, going to the medium cured that. IMO there's something going on with your grip; the VP9s have a reputation for excellent accuracy and the 9x19 M&P 2.0s have a reputation for being pretty good as well, that much of a difference shouldn't be chalked up to the guns themselves.
Re: the VP9 not liking steel and aluminum cased ammo - lots of pistols choke on this stuff. It's made to a price point, which implies that production tolerances are going to be funkier than good ammo, and if your chamber's cut to minimum dimensions (pretty sure that's the case with the VP9, it is with my Walther P99C) it's going to be pickier.