I just purchased the Khartago amp.  Maybe I am not listening to the right source material but I cannot hear any improvement over my 145wpc THX ultra Denon AVR-4800 amp/receiver.  In fact the khartago appears to be slightly softer than the Denon was.  
I called Klaus and told him they sound the same but he suggested I give it more time to break in.  Perhaps I have made a mistake with going with the Khartago and should have picked the 150wpc stratus.  Klaus seemed to think the 110wpc khartago was a good match with the Denon.  But this is not your average receiver/amp.  It is pretty decent.  It was well tested without distortion at 143wpc.
Any CD suggestions to A/B with the Khartago?