I do know that when you raise any speakers 2-3" higher it will change the sound and imaging. The tonal balance will change no matter if it was a wooden stand, bricks, or anything else due to the height difference and its impact on the bottom end which supports everything above.
I have found my M3's have sounded their best just on their own front feet with no spikes of any kind. I have to thick carpet with a 10lb carpet pad below with a 3/4 inch plywood floor nailed to studs. The dynamics, detail, transparency, body and weight, and a, even more, deeper, and more defined bass. Even those who have stopped by to listen I will put the spikes on and play the system with their own discs and music, then later I take the spikes off and play the same discs of theirs back over and wait to see their reaction, in every case I get a whoa, man does that sound better, to your telling me just taking the spikes off could not this? It sounds like a different speaker and for the better. My speaker is decoupled without the spikes and it cost me zero. I never like spikes on many speakers, even my Quad ESL 63's turn that speaker into a transistor radio almost but yes, it sounded different alright, nice and clean with not much else left, oh the bass was supertight to almost no weight to it or tone, color or body.
Tomorrow I going to pull my Mark Levinson 300 watt amp out of storage and me my Mcintosh to the side. I have a feeling this is going to be something special because the ML was current feedback-driven over-voltage and it had a subterranean bass, with a very open midrange and analog-like highs. It had dynamics that were jaw-dropping with my Dynaudio Confidence 5's. I have the matching ML 326S preamp also that will be going into the system. Both are hardly used with maybe 200 hours on them. With my purchase of the Quads, I added the McIntosh's into the system and I loved that combo for 10 years.
Certain gear you buy is special and that is when you hang on to it even if you make a change just for change's sake as I did.