It is not a filler product. When it removes the swirls, it really removes them. Here is an example of a hood I polished with DACP (#83). Here is the before:
And here is the after. I tried to get it at the same angle. I have no idea why it looks like it is a different color other than the fact that without the swirls all over the place the camera may have been able to focus a little bit better. This is after maybe five or ten minutes worth of polishing with a Porter Cable 7424 and Meguiar's #83.
Those swirls are not just filled. They are absolutely gone. You can check the work of DACP by wiping down the area with isopropryl alcohol and seeing if any swirls come back. rubbing alcohol will remove fillers. DACP is not leaving anything behind that hides swirls. It is also a product that is only effective when applied with a machine. I would not suggest even attempting to get results like that by hand with this polish.