It's not so much that it's DC, it's that they're unproven. Or, in the case of some DC pumps, proven to be unreliable. It's also not just the pump itself, it's the transformer. That's a real weak point in terms of reliability.Im on the DC bandwagon. I feel its similar to when LED's hit the market, many spoke out of fear but eventually the majority switched over
A failing LED light won't kill your tank over the weekend.