@maxwave Unless I am mistaken the output section of these amps are solid state. The tube is only in the pre section. This should not affect bass output. Also there is a difference in power between the amps. The Dag were 400w into 8ohms and 800 into 4ohms.
Again this is only my experience having owned the Atria II with the Momentum gear. We all hear things differently and have different preferences too. That is what makes this hobby great.