Don't mean to hi-Jack but the Fiveseven isn't really a "gimmick" handgun at all.
Roughly half the recoil of a 9mm, with the FN ammo extremely accurate, pretty good factory triggers
And very reliable. Also flush fit 20 round mags, extended 40's are not bad in the gun to carry. Shooters tend to shoot the gun very, very well, extremely low recoil guns are often shot well easily.
With duty ammo penetrates all soft body armor. True stopping effectiveness is debated but if shot with one you are dealing with a hole and lead in you, regardless of any soft armor you are....or are not wearing. This was part of the NATO RFI.
Rich