Mr. D'Agostino is a legendary component designer, one of the most respected. His Momentum line sits just under the unobtainable level of D'Agostino products. He has a very loyal following of high end buyers cultivated over decades. Your Burmester is a beautiful integrated and I'm quite satisfied with my 218. Have we reached the pinnacle of what's possible? No, far from it, even in the Burmester line.
Why would someone buy the D'Agostino? The easy answer is that they like it and they can. Its voiced a little different than Burmester products and that integrated is a beast. 500 watts into 4 ohms, and a striking piece of gear. So, for someone with the budget, power hungry speakers, and attracted to the convenient solution offered by integrateds, the D'Agostino would certainly be a consideration. Horses for courses. That's a bunch of money for an integrated, but I suspect it will be a successful product.