The hercules will take far more abuse than the Bxi2006. As far as hearing difference, i coudn't tell ya even though i heard both amps. It was in different setups, so box, subs and car had a impact on how loud it is.The bxi2006 is a solid amp though.
you might hear a difference. the BXI2006D does rated power while the hercules is underrated. i have even been told that the hercules will run at .5 ohms all day
im glad im hearing good things about the hifonics bxi2006d. i just ordered one off of ebay for 340 shipped about 10 mins ago. ill let you know how it sounds pushing my tumult 15.
hercules is like they saying very underrated,its a real strong amp,more of a comp amp,where the 2006d is a good daily amp,they both good in thier own way,hercules cost more.