I used to own the Sigma AMP2 but sold them to free up funds for bigger purchase. I thoroughly enjoyed them during my time and wouldn't mind owning them some day again, specially due to it's size and weight. Even though they are class D amp, they sound better than a lot of other amps I've owned (e.g. Anthem, Emotiva, Parasound). Only my Classe Delta and Pass Labs amps were better.