I think supports definately can make a difference, but like so much in hifi everything gets so ridiculously blown out of proportion.

For example.. putting my gyrodeck on a solid wooden box makes it sound the same as the top shelf of my target stand, and it also sounds the same on the floor.

Putting some Michell cones/cups under my CDP made a small difference.

I saw one bloke on this forum say he could hear the difference between different types of rock when used as a base on his rack!!!! Im sorry, but I strongly doubt that this was anything other than psycho-acoustics.

Concrete pavers under the speakers makes a real difference too, in fact isolating the speakers made the biggest quantitative diffference IMO - compared to isolating other parts of my kit in the past.

your mmv of course