I see very few problems with P-11s on the KT sites. It isn't a Glock, but if you do your part and keep it relatively clean and lubed, it will be reliable. Like all carry arms, it should be tested, of course.
Whatever works well in your particular P11 is what you should carry. I personally carry Hornady XTP 115 gr. My P11 chokes on WWB fmj, but all other ammo feeds nicely.