I purchased a pair of the Evo 400 Power Amps and the Evo 400 Preamp last week. They are delivered and sitting downstairs but I have not heard them yet because I'm waiting for other equipment to arrive. The local distributor has the Evo's installed as well, and he told me via phone that there is a strong improvement in sound quality over the Dialogue series. I can't personally confirm this, as I have not heard them, and I never heard the Dialogue series either. But I can confirm that the amps look amazing and the build quality is the best I have ever seen in any amplifier. For me they replace an ARC VT100 original model which died a few weeks ago which I have owned since its release, and an ARC Reference 2 preamp which I still use. I also own Coincident Reference line and phono preamps which I rarely use although they are very good. When my other equipment arrives in about 10 days, I will report on the sound of the Evos if anyone is interested.