Made in Italy vs USA is really just a matter of personal preference. The guns are made to the same specs. I love the 92 and I've carried/shot many well used ones while in the Army and also have one of my own. They're very accurate easy shooters. I like old school metal guns and the 92 will always have a place in my collection.
For all intent and purpose, there is no difference between the American made and the Italian version. Other than the country of origin, they are both made on like machines held to the same tolerances.
The "F" was an update of the "SB", improving parts and changing the shape of the trigger guard. The "FS" changed the size of the head of the hammer pin, as stated earlier, to protect the shooter in the event of slide failure.
While some people say that the Italian is better than the American, or the American is better than the Italian, it mostly is because on the day that specific pistol was made, the Bruniton process was just recalibrated, or the milling machine was.
I don't think you can go wrong with either Beretta 92FS, I like the newer models also with their individual added features. The Brigadier, Centurion, INOX, Vertex, and the newer ones the M9A1 and the 90-Two with all the added bells and whistles.
I have a couple of them with one that I carry alot has digested over 30000 rounds of 9mm over the years that I have owned her... Good gun, good manufacturer, solid performer...