I don't care about who says what about numbers, air, pump or ratings...all i know is that i believe my eyes more than others peoples' opinions..and after owning a bubble king, a vertex alpha and 1 atb 840, i can honestly say that i will most likely stick with atb. Over the years, i wanted to hate atb, but the fact of the matter is that my current 840 has pulled the most gunk pound for pound or shall i say liter per liter than any other skimmer i have owned in the past 12 years. some people are loyal to certain brands while others just troll to get a rise out of people but i personally have no allegiance to any brand..i just want the job done and done well and atb has delivered so i have nothing but great things to say about my atb skimmer...guess i better fork out the money for sponsorship as well. lmao.