REL Strata III spikes

I have a REL Strata III sub. The interior of the feet have threaded holes that I assume accommodate spikes. Did spikes come with these subs when new. Assuming they did, is anyone using spikes and is there a noticeable difference? I'm wondering if spikes with floor isolator discs on a wood floor would make a worthwhile tweak.
I don't know for sure but the manual talks about using the spikes as if they were included. I talked to Sumico about them and they were clueless, suggesting I talk to a dealer. As I understand it they not only import REL but now own the company so they should know if anyone did. They have fallen a long way from what they were in the old days when I was a dealer for them. The cones I mentioned have a matching cup available for wood floors.
The Strata originally came with spikes and Sumiko recommended to "not" use them. I don't with mine atop a sandbox.
Forget the spikes and forget the rubber feet. You may get better sound with your Strata III by doing what I did.

Turn it upside down and put a board on the now upturned rubber feet, with something weighty on top of that board. You may have to turn up the volume level a bit on the sub, but the bass should get tighter and more tuneful. I also found, contrary to common "wisdom", to keep it out of the corner.