N2Audio
if you go in with that expectation you'll likely hear problems regardless. Full range class D's have become fairly common over the last 5 yrs or so and a lot of people have been very happy with their performance in terms of sound quality -- me being one of them. Does this "consultant" have a shop where you can listen to the Alpine vs some more traditional type amps to verify whether or not you can hear what you think you might hear? That's probably the only way you'll be able to answer this question well enough to convince your ears what specs you can actually hear.