Supposedly, the PX4 has interchangeable backstraps so that you can make the grip thinner/thicker for your own personal needs. However, BerettaUSA, in its infinate ( :roll: ) wisdom does not put the smaller/thicker straps in. You have to order them special.
I've been looking at it for a month or so now. The reason why I'm still undecided is that they don't come with factory night sites (there this supernovia crap - flash a light on it for a minute and they glow for a while), the trigger pull is horrible (at least the one I looked at), and, basically, its noting special.
That, and my honest belief that Beretta is screwing the pootch and fucking over the american handgun market, and thus I don't want to give them any more of my money, has led to my reservations. Your better off buying a Glock 19/23, at least its a known element in the marketplace.