I have experience with the Hafler 500. I once ran 4 kappa perfect subwoofers for hours with one. The subs were wired in parallel pairs, giving the amp a 2 ohm per channel load, and it did it with authority. I can't speak for the Aragon because I've never owned one, but I'm sure the 500 will do the job well. The big drawback with the 500 is if something goes wrong, and you need to replace transistors, there are no current replacements, and the originals are very expensive.