How important are spikes?

Iso Acoustics makes very good isolation feet for speakers ,

I’d have to imagine rubber feet produce a different sound than spikes and each has their uses, and then there’s always personal taste. I always thought these Gliders from Herbie’s were a neat alternative to spikes as they allow for easy movement and also provide some meaningful isolation, and users give them high marks for both convenience and sonic improvements. That they’re relatively cheap is an added bonus.

https://herbiesaudiolab.com/products/threaded-stud-glider

How important? Very little importance…. 

Speakers a little different. Rack of electronics. Not so much. If worried about it buy some decoupling pucks to put under your components.