@toddverrone. You ask about what to expect from spring isolating your speakers if on a concrete slab? This is exactly the situation I am in, albeit the ground here in NW Portland is quite soft and transmits seismic vibration all too well.
Isolating your speakers on something like the seismic podiums will radically change the way you perceive bass. You will no longer feel bass transmitted via the floor and at first you may perceive this as a diminution in bass but at least in my setup the bass transmitted directly to you is better defined with greater clarity in subtle details and also greater differentiation between shades of tone and timbre. There’s a fuller description of my experience here
https://forum.audiogon.com/discussions/speaker-isolation-experience-with-townshend-seismic-isolation...Seperately i I suspect you may find a different effect from roller balls. I have these under all my stands and the effect is more to tighten things up, much like adding herbies dampers to tubes. Oddly when I put apex footers under my power amps it seemed as if the volume level dropped - this is usually a sign of a reduction in the noise floor so I think that’s what the balls do, they help remove vibration manifest as noise. The podiums are quite different in effect