The AI mag may win hands down, but youll have to ask yourself if that is worth paying 100% more for a rifle. You could also convert the new fcp to accept AI mags by swapping the bottom metal and buying a mag for right around $300 I believe, which may still be more cost effective than buying the older model that is already set up for them. Decisions, decisions. Or you could just buy a chassis that accepts AI mags and not worry about it! :)