Hell no! A lot goes into truly professional gear having nothing to do with the sound quality. Plus high-end gear does sound excellent. Besides raw fidelity, which is not difficult to achieve these days, there's also build quality, features, stability, reliability, quality of the drivers, and more. A real studio like, say, Universal records 80-piece orchestras that cost thousands of dollars per hour. They're not going to dick around which cheap crap that might break at the worst time. If a Behringer DI costs $30 and a Radial or whatever costs $200, they'll gladly pay the $200 every time without blinking.
--Ethan
Sure... I know you say that "stacking" is flawed, but I don't think I'm way off base here. Speaking from experience -- anything that I've ever recorded with high-end gear has always been easier to mix. I'm talking about rock & roll/metal type stuff. I don't think it has as much to do with the sound of one individual track, but more with how all the tracks play together. As a whole, everything has more dimension and punch when tracked with anything considered "pro" --- this is what I was talking about when I mentioned "accumulative effect" --- so, I'm still curious as to how multiple tracks from each converter would sound. Especially with music that's more willing to exploit the sonic limitations of said converters.