I just sold my Arcici Suspense rack after many years of ownership and have installed a Samson v3 from Mapleshade. I've been doing exactly this comparison for the last two weeks. I still use acrylic sheets under two very nice but light and ringy 45 tube amps. They're not placed on the Mapleshade.
Acrylic is very much a dampener, but if your piece is well built with good feet, the 2" Mapleshade shelves do a good job. NB: I still use Bear Feet, sorbothane and Sound Tech, and Walker Valid Points under my equipment, so several of my pieces are not on naked maple shelves, for the most point.
However, my very brief experience with Mapleshade makes me think they have something to say: those pieces directly coupled to the shelves with heavy brass cones do seem to sound better, to the point where I have yet another set of Valid Points on order. Yes, the Mapleshade points are real good, too.
However, those are pieces that I've CHOSEN to put on and install in that manner, simply because they sound better that way. I don't think there can be any one answer: it depends on case material, density, and even location of the feet due to resonances and location of circuit boards.
I like the Mapleshade and its substantial feel. It is certainly stable and I voted with my pocketbook on that: that way, what I put on it at least has a chance to be effective. The Arcici is unbeatable at damping 'RINGY' stuff, but some of my pieces sounded "dead" on it. I can't liven up an acrylic sound, but I can dampen Maple. I like that option.
Perhaps THAT was more accurate and my mucking around with different feet, etc. made certain gear sound less accurate/"like itself". I tune items and their feet, etc. to the shelf they sit on on an ad hoc basis and trust my ears. I have no univeral theory on audio or much of anything else, truth be known. Interactions seem to be the heart of it: none of our equipment funtions in isolation.
I could live with either one, but the Arcici is $3k and the Mapleshade (just for two examples) is a bit less. You could buy and experiment with a few/several types of footers with the difference in price. Acrylic sheets, even nice moderately thick ones, are fairly cheap. Order one or two and put it under a few pieces of your equipment and experiment.
Oh well: YMMV, which makes this hobby more fun and too expensive at the same time!
