@RonP and @franSSS
I have a full basement and this is a thickly carpeted suspended (I guess that is what you call it) floor. I didn't realize how much sonic mud was coming from having the spikes through the carpet into the subfloor. Until I did this. Everything tightened up a bit, and especially the bass which became more tuneful and less muddy. And I am tall, so the increased height has been beneficial too.
The little pads are industrial vibration absorbing pads. But given that they are on thick carpet, I doubt the absorption properties are a factor. But the ribbed surfaces, while not sticky rubber (they are actually very hard rubber), do indeed provide a no-slip contact above and below, which I think is important. I have not tried a commercial product under the X5's, so I can't say how they compare. But for what it costs, you'll lose little in trying.
I agree that is looks a bit funky. I could get a couple of pieces of good hardwood, oil them, and replace these pieces of pine. And actually, maple would probably tighten things up a tad more.