At least on my FNP the fire control group is mostly polymer, yes the trigger is polymer.Barrel, slide, fire control group are metal. Frame and safety/decocker levers are poly. I think the trigger is poly but I'm not 100% sure.
The FNP was a pretty good deal 4-5 years ago when you got the gun and 3 mags for around $300, but at $550-$600 for the FNX, there are better guns for the money. I especially like the Walther P99, with the price drop it's now the same price as the FNX but better ergonomics, a more solid feel and a much better DA/SA trigger, the FNP/FNX DA trigger pull is pretty heavy.
I did not feel much difference between S&W M&P, XD or FNC product. The one that felt the best was called Steyr c9 or m9. I have no experience with this gun but the company makes good dump trucks so perhaps their pistols are also good tools. Guess I like modern striker fired auto with 4-5lb trigger and short reset.For those of you that have handles or own one, what are the good and bad of these? Possible interested in one in 9mm. Never owned a poly gun before.