I have not shot the FN, but have held one, and were it not for the fact that they do not make one in .357 sig I would own one.
I have shot a G19.
My main EDC's are a S&W .357sig c and a Sig SP .357sig 2340, which is almost size comparable to the FN as well.
They are big pistols, but not too much bigger than your G19.
It will outshoot your Glock all things considered equal.
They are IMHO a better, more solid feeling firearm. YMMV
Go to the FN website and you will quickly realize you are NOT dealing with a rinky-d i n k company.