Do stands make a difference for equipment?

I think that there is no substitute for a solid and massive rack. I also think that mixing materials lessens the likelihood of developing resonances. Sooo...I built my own.

For the vertical supports, I bought eight decorative concrete blocks and painted them with white semigloss enamel. I applied heavy felt to the top and bottom of each block.

I made the shelves from 1/2" granite tiles laminated on top of 1 1/8" high density fiber board. The mortar for the tiles acts as a dampening material. I edged the shelves with oak door stop stained semigloss black.

The whlole project cost less than $300. The beauty of it is that you can use any color granite (or marble) you want and you can paint the blocks any color you want.

I put one self directly on the carpet and built up from there. The rack is 78" long x 27" high x 17" deep. It weighs about 500 pounds. It has a total of 9 spaces (including the top)

Just a quick update. I ran across a good deal on a Solid Steel 5.5 demo, and pulled the trigger. I've been wanting something a little bigger than my Target 5 stand since purchasing my Krell Phantom III pre, which barely fits on the T5 rack.
The biggest difference in construction of the Solid Steel and my T5 is that each shelf is supported by 3 cones, and the T5 shelves were supports by flat corner tabs.
Even though I had filled my T5 with lead shot, I tried the new SS without shot first, and was surprised that it did clean up the sound a bit. I then filled the SS with shot. It only holds about 1/2 the amount that the T5 would because only the leg tubes are fillable. The T5 would allow shot to get into the cross bars as well. Still the lead did make another slight improvement. The results are a quieter background, wider and deeper soundstage, allowing a bit more fine detail through.
Now this isn't an enormous improvement, but well worth the cost of the rack. So in my case at least, racks do make a difference, but I didn't spend thousands on a rack either. Now the question is, how much do you have to spend to get all the improvement available? Will a rack two or three times the cost of my SS give that much more improvement, or will the diminishing returns set in quickly with a rack? As with any tweak, I realize the system it is used with will have an impact on how much the tweak is noticeable, so ....?
Any more thoughts?

Try Symposium Ultra platform it will improve everything.

A Symposium Ultra under my toilet will give me a "E"xcellent "B"owel "M"ovement? Just kidding :)