When I purchased my Rel,Sterling Trayle was still employed with Sumiko,the distributor,at the time.He strongly emphasized that I did NOT use spikes.He felt that the REL was designed to have a certain distance from the driver to floor,and the spikes could,would screw this up."Pressure loading",had to be correct,according to Sterling.Makes sense,to me.
In any event,with the numerous little movements I had to employ,over time,I think that had I used the spikes,I NEVER would have been able to easily move the SUB into optimal position,as I have.The current sound is seamless,and I know everyone who spends DOUGH is compelled to feel this way.In my case,as others,I'm sure,I could not be happier.Good luck!