Any time the term "Cop Killer" is used, you can be fairly sure that it's the Anti-gunners up to their games again. They must demonize something. Right now extended Hi-cap mags are on the hit list.
The FN is a pretty nice piece. Think of it as a very expensive .22 and you're close. I wouldn't consider it a good concealed carry gun, it's pretty large. While it is a lethal caliber (as are most) I wouldn't consider it a reliable one shot stopper. While the numbers look decent on paper, bullet mass matters. A 9 mm or larger would probably be a more practical choice.