The BEST??? Well, that would be certain robotics. I have an AG (with a deepend) and I am thrilled with my Dolphin Dynamic.

But if by "best" you mean best dollar to performance value, look at the Polaris 65 too.

Vacuum side cleaners ensure the junk is trapped in the filter, but they can be weak.

Return side cleaners are like a pressure water that blows the debris into a catch-bag--which can allow stuff to pass through. A handful of cotton balls can improve the filtering.

Don't know anything about the aux. pump types.

Robotics do the best job, and cost the most...Some, like the AquaBot, have a rep for being hard on the liner and are better for plaster/concrete. I have not had that with my Dolphin. All of them filter as well as a DE filter--if not better. The catch bag is three or four layers, kind of like sweatshirt material and very, very fine.