I found the FN 5.7 to be over rated. Ammo cost is high
FN ammo can be had for $20 a box of 50rds, and is useable for hunting or self defense, not just plinking.
Seems rather cheap to me, honestly.
performance in various mediums questionable.
Depends on the load. Top Elite and FN SS192/198 loads are extremely effective barrier penetrators, will blow right through soft body armor, and yet still blow through 12+" of bare gel.
Recoil seemed to be similar to a .40 S&W, however performance was comparable to a .22 mag.
I must question if you even fired a Five SeveN at all. Recoil is more like a .22 mag than a .40 S&W. The Five SeveN, even with the hottest loads, has very little recoil at all.
As far as terminal effects, Brassfetcher labs gel tested the Elite S4 round and stated as follows in the summarized report:
"As tested, both 5.7x28mm cartridges (Elite S4M and Elite Protector II) offer lethality that is on par or slightly greater then a .45 ACP 230gr Jacketed Hollowpoint. (Round shown was the Federal 230gr Hydrashok JHP)."
It further states:
"Conversely, the FN SS192/5 and Elite ammunition S4M offer performance quite similar to the tested .45 ACP, with considerably lower recoil and ammunition weight, coupled with a significantly higher magazine capacity.
We feel that the S4M can be viewed as a "+P" version of very effective SS192/95 27.5gr, and we have no qualms about recommending this cartridge as a feasible replacement to the more conventional .45 ACP handgun, for use against human attackers."
Link Removed mmary.pdf
Here is video of an S4 gel test:
1&feature=iv
Seriously, you are making completely unsupportable claims in your post.