I play blades, the Accuform Canada PTM irons, 3-P. I have another set of blades, Wilson Staff DynaPower, 2-9. I tried cavity backs, I don't like them.

From my experience, the difference between a mucleback blade and a cavity back is the amount of feedback they give to the player. The blades give the most feedback while the cavity backs give the least amount of feedback. This means that blades will hurt on bad hits while cavity backs will not. It also means that a player using blades will learn much more quickly how to strike a ball properly than a player using cavity backs. Combine this with the shaft flexibility and you could get any amount of feedback you wish. The pros prefer extra stiff with blades, in other words they prefer maximum feedback. A side effect of this tremendous feedback is that the pros have maximum control of the club and the ball.

Conversely, you could say that since cavity backs give the least amount of feedback, they allow the least amount of control.

All other stated differences are simply marketing hype. Except one, if you do not want to improve your ability to strike a ball properly through extensive practice, use cavity backs so that at least you won't hurt yourself striking the ball improperly. Which by my understanding, will be quite often.