jeff, I honestly can't say I noticed a big difference.
Right now, making this sort of subjective assessment is very hard. I'm one who agrees that a lot of things affect my ability to judge music quality from what mood I happen to be in to which model of leaf blower my neighbor is running outside my window. I also think it is very easy to internalize what I hear from others ("it will sound better with spikes") and to yield to my expectation of improved quality based on having taken the time to make these i.e. I've gone to the trouble to make them, surely it must sound better. And then I fight these expectations trying to be objective....and the end result is that I don't know.
I'm listening right now and they sound marvelous. Better than before? Probably. A revelation? No.
As for the OEM bases, they are rectangular channel steel, 4 pieces welded together and there is clearly something in them because they are heavy. I know they are OEM because Aerial sent me a schematic.
I am no machinist. You can tell that by looking closely at the picture I posted of them. I have a grinding wheel, a drill press and an angle grinder. All of them old. And no training. Any pretense at craftsmanship in my posts above was purely for humor.
