I never really put too much stock into "hitting hard" until I threw my old Reactive Flame. One night I was throwing my Qunatum in league and crushing, until the shot dried out and it started to go a little high. The last game I switched over to my brand-new Flame, only to leave the 5-7, two 8-10s, and two 5 pins. I went 230-230-170. That was with only missing pocket once the final game.
I think that "hitting hard" is usually referencing carry, which we all know is about 90% entry angle. So, I suppose it’s possible for a ball to “hit hard†on one shot and not the other. Still, I believe there are some balls that just are not ever going to carry or “hit†as well as others.