Is there actually any concrete evidence (at least for non turntable use) that heavy and expensive racks (+/- spikes and vibration control), make any significant audible difference? Aside from the "eye-candy" effect, I don't quite get it. My system is essentially comprised of non-moving parts (95% of my listening via my Squeezebox into a Benchmark DAC). I am currently using an inexpensive StudioTech HF-4 modular rack (with casters on carpet), and even when cranking out thunderous bass tracks, there is virtually no vibration/resonance. To me, if anything, it makes more sense to add isolation feet, or perhaps a heavy weight on top, for any components that appear to resonate. Yet, I see so many audiophiles investing significant $$ on high-end racks, even when they don't have an analog setup!