D’Agostino Momentum stereo vs D’Agostino Progression Stereo Amp

I probably cannot provide you with information as relevant as Mribob, but for what is worth, I purchased a used Dag Momentum integrated to replace my excellent Accuphase E550 and realized a vastly deeper soundstage as well as a cleaner and finer-grained audio with my Sonus Faber Amati Anniveraries.  The sound is more relaxed, transients seem faster and is more transparent with more "air" around the instruments. I expected the bass to be "tighter" as well with the far greater Dag current, but this was the one disappointment although I am still satisfied with the bass. In all, I am very satisfied with the equipment and have had no reliability issues to date.   This is the only comparison I can provide. As far as Dan Dagnostino is concerned, I called the company to ask questions regarding power cords and interconnects. I was told that I would receive a call back the following day. I did, from Dan himself, who was willing to spend all the time I needed for my questions even though he knew I purchased the Momentum used. He invited me to call any time. Says much about the man and his company in my opinion.