I have not found any universal rules in this area, and it seems to depend on a number of factors. For example, with the hybrid Logans, rigid coupling to the floor is critical or the bass unit does not integrate at all well with the panel. But with very hard floors, or where you need metal cups under your spikes, then spikes can sound horrid - BDR cones being much better.
Cones vs. factory spikes?
Has anyone done any A-B testing for various speaker cones? Currently, my KEF REF 4s (120 lbs each, ported base) have the factory spikes. Before spending big bucks on Orchard Bay cones (used on Talon Khorus and recommended by my dealer) or Black Diamond Racing (why is their web site is abysmal?), I would like to know what others have used on the bottom of their speakers and if they make an "audible" differnce. Rest of system (for 2 channel) is: Aranov tubemonos, firstline pre, Sony SCD-1 (on order).