Energy damping or energy transfer?

Are there some generally accepted guidelines about which components to isolate (in terms of vibration damping) and which components to "couple" to the rack (which is also coupled to the floor)?

I freely admit to being clueless here (I'm still trying to get my head around cables and power cords), but it seems like the "brass spikes" guys are saying something completely different from the Vibrapod-type isolation guys.

Given what they're asking for these products and the potential number of components involved, it's like considering a major component upgrade.

Also, has anyone noticed once a component is isolated/coupled that either the interconnect or power cord is affected? Thanks. If this has been kicked to death in the past, just posting a link would be great.