Has anyone tried the FN Five-seveN?
It seems very interesting to me. Some interesting features: Lightweight, 10,20,30 round mags. 5.7mm high velocity 27 grain bullets which tunble on striking.
Downside, expensive, hard to find ammo, stopping power really unknown.
Roger that.
5.7 is my go to round for a whole host of reasons.
The only legitimate downside of what you've listed is the price of the weapon. Ammunition is very reasonable and available albeit by online sources.
There is a real issue to be aware of though. This particular round is VERY sensitive to changes in bullet weight. Point of aim vs. point of impact can vary up to two inches between 27 grain vs. 40 grain loads...AT SEVEN YARDS!
Any general change of ammunition should be followed by a sight adjustment.
That said, I don't know any other pistol where I wouldn't feel outgunned by an AK ;)