I think a big part of the sound difference is that Acurus is made by the same people as Aragon and they market Acurus as a more affordable option than the Aragon amps. I have heard both as I almost picked up both brands when I worked in high end in the 90's and they are quite far a part as far as sound quality goes. The designs that they sell today are basically improved versions of the same I heard in the 90's if I remember correctly so that would be more of the factor than whether its a monoblock or duel mono in one case or a 4 channel. I look more at the performance of the amp than the type of amp. I have heard stereo amps I love and monoblocks I didn't. Me and Mr. Peabody both agree on this point.