I currently own the SDS254 ClassD Audio amplifier and also got to hear the Ncore tour model amps. I started with a CDA series and upgraded to the SDS and it had much greater control, less distortion and better dynamics. The Ncore was a similar experience, much better control, dynamics and resolution, the bass is tight and abundant. I could easily do without an external sub while using these amps. The gap between the two upgrades weighed more toward Ncore, its distortion levels are clearly exhibited in its sound. At well over twice the price the Ncore is clearly superior but the SDS is no slouch at its bargain price and responds well to mods.