Hardwoodfloors and Spikes

LOVAN Footers will protect your floor but yet allow you to use your spikes.

I'd recommend going straight into the floor with the spikes. Putting anything between the spikes and the floor begins to defeat the purpose of installing the spikes in the first place.

And provided you do not drag your spikes across the floor the tiny indentation is so miniscule, only you will know they are there. (assuming of course that your speakers do not weigh 800 lbs each)

-IMO

I'll second the spikes (or cones) and coasters from Sound Anchor. A great side benefit of the coasters is that they are a felt like material on the bottom and I can move my Europas and Sound Anchors easily on the wood flors to try different speakers positioning. This at almost 100 lbs total weight.
Rubber sounds---umm,let's see----oh yes, Rubbery!

Conecoasters from Soundanchors @ $14.00 each work great for me with spikes on my oak floors. My rack weigh 600+ lbs. with gear, if I went straight to the floor with the spikes the points would be visible in the basement! I also use Orchard Bay points, & pucks under my speakers. The only time I ever used rubber was under down firing subwoofers to keep them from moving around.

Some people who have tried both spikes and softies prefer one and some prefer the other. As I remember a lot of those who use rubbers, utilize them in a slab sandwich - more fun, less attractive. Spikes appeal to me only because their purpose is to better inhibit speakers from rocking. The energy used in rocking is information lost.

I used to have a house with hardwood floors; thought the discs 'n spikes worked quite well, but never tried squeezable alternatives.