I could not agree more. I only work the ball if there is something to be gained from it. This is usually 2 or 3 iron shots per round for me, usually after a poor tee shot into the edge of a wooded area. If I only have a clear shot to the left edge of a green guarded by a bunker on the left, I will hit a slight fade (3-5 yds) at the left edge to give myself a better chance at hitting that green and avoiding the sand. I'll do the same thing with a draw if the situation is flipped. If I have a straight shot to the green, I don't hit a big, sweeping hook just for the fun of it.
The main reason for my original post was to determine if it would be easier to control trajectory with a set of player's cavities. I'm very happy with my current irons, but once my ballstriking improves enough to warrant it, I think I would like the increased workability this type of iron would offer.