Most balls are similar off driver and mid irons. The differences probably are not noticeable to most golfers. The difference is in the approach, chipping and iron shots around the green. For me, this cost me a stroke yesterday. I almost landed a Bridgestone e6 two piece golf ball in the hole from 100 yards out, divot was an inch from the hole. The ball rolled out another 10ft and I missed the putt. A tour ball, Snell mtb-x, would have stuck and not moved based on me hitting that ball.
I'm to the point to when I start hitting more greens regularly then I will make the switch.