Hi EJ and Ratso1,
As the reviewer of the A$$Audio article, I'd like to point out that I did mention more than once the cost difference between the two. That said, my reviewing style requires a comparison with a reference and I accept I rely on this more than some. Frankly, I am tired of reviews that speak of a component being good, having such and such a quality, this or that ability, without specific reference to another component with its own qualities. Since most components that make it to a review usually perform at a level of competence that means they will sound pretty good in most systems, the comparison with a referent is the only way to provide some benchmark for real distinction between components. Rather than just saying I liked the W4S, or I liked it more or less than the BAT, my reference, in a final paragraph, I invoked the comparison specifically for each relevant quality I wished to describe in the amp under review (bass, midrange, treble, soundstaging etc, and yes, price). I realize companies might prefer a review in the abstract that talks about the qualities of their product, and interested buyers might wish to have their interests confirmed with a uniformly positive or negative review, but it makes no sense to talk about product A possessing a "great" treble or "strong" bass if one cannot point to a reference among other products for this quality. I believe I said more than once that the W4S made a very positive impression and even out performed the BAT in some areas but not all. For the price, it's hard to beat, but if you spend more, you can get more, and in my humble opinion the BAT is better, but not by as clear a margin as some might expect.
More generally, Class D is invoked as the breakthrough for amplification, and if this argument is to have merit, we need to put such designs up against other products that committed audiophiles might employ. You can find a used BAT VK500 for $2k on A'gon...I think the comparison with a new W4S is not as far fetched as some might think.