Tough=repeat playability. Punishment=sell it and move on. This game is right there. On the cusp of frustration, then you stack modes, and get the multiballs moving, you love it.
When the initial pf design was released, I called my friend at Stern and told him everything I thought was wrong with the design and how I may have made a mistake buying sight unseen. He assured me it was going to play awesome and to not worry. Glad I listened. (I usually do.)
I would call the pf design brutal, and the rules rewarding. A strong mix like this happens in few titles. I can see this being a keeper.