The FMJ is a wonderful arrow material. I find them to be a little stiffer than a larger diameter carbon with the same rating. But, then they are smaller diameter and my bows are not cut to center.
I used FMJs in Africa, and was very happy with them for such an expensive hunt. And I shot them for all my practice there-whether at a hard target or not. That's the one qualification I feel many don't take into consideration. It is much harder to find an arrow that flies like your FMJ AND costs less. The small diameter does make a difference, and I consider stumping...or whatever you call it....to be an integral part of my practice.
If I were a millionaire-or if all my other arrows disappeared tomorrow-I'd simply go to FMJs and never look back. But, that's not the case, and when I'm looking at $10-25/arrow(depending on the point, insert, etc)......it does give cause for thought!