How much difference do stands make. I'm not talking about stands vs. no stand, I mean different stands of the same height. I hear people speak of "heavy" stands, or "solid" stands, or ever stands filled with sand or lead shot. What's the deal?

I'm currently using just about the cheapest pair of stands I could find. My M22's sit atop, and they have spiked feet for the carpet. They probably cost no more than $40-50. Will a more solid, heavy stand make an audible difference?

Thanks!

-Craig