@sidog1460: The question of whether to isolate components individually vs. install Townshend Audio Seismic Corners on a rack is an interesting one. The Corners isolate the rack and everything it supports from floor-borne vibrations, but do nothing to isolate each component from the rack (and it's shelves) itself, and from the other components resting on other shelves.
But since you are already using the excellent Symposium Rollerblocks and Platforms (which---unlike spikes---do provide isolation for each component), the addition of the Townshend Corners would be a good way for you to access the effectiveness of the Townshend Seismic products. And there is no reason the Symposium and Townshend isolation systems cannot be used together. I have owned the Symposium Rollerblocks (and the very similar version of same made by Ingress Audio Engineering in Canada), and currently employ both the Ingress and Townshend isolation products in my Solidsteel racks.