DACP may be more aggressive by PC, not by the rotary. They pretty much accomplish the samething, no need for both.
I know there has been alot about IP not being real aggressive around here lately. Its simply not true, try it with the rotary for optimal results.
Also a difference in how you use the products. With Menzerna and the PC use very little. Using too much the product will never break down and you'll be working it in and smearing it around forever with out any results.
Try using about a quarter size in the middle of the pad.