alternatives to spikes on wood floors?

Right on Richards! I, too, love the Aurios! I think that they tighten the bass (although upon first hearing, some people perceive less bass. This is actually the removal of distortion artifacts, which can produce a boomy bass). Imaging in the sound stage also improves!

To make leveling with spikes possible without puncturing the wood floor, I chamfered eight pennies in their centers with a quarter inch drill bit and put these under my spikes. Cheap and easy!

The spikes may not be needed at all. I once had my Thiels on hardwood - made no significant difference with or without the spikes (I spiked them on thick ceramic tile) in my room. The purpose of the spikes for Thiels, IMO, is more to couple the speakers to the floor over carpeting than vibration control. The Thiels are very very solid, so I don't think vibration is as big of an issue with them. In my opinion, I don't necessarily agree with "... I know I should be using them up on the spikes ...". Of course, your situation is most likely different than mine - my speakers are placed where the side and rear walls are not a significant factor.

Polycrystal makes a product called "cone-coasters." You can read about this on their website. I had the same problem you had. Cone-Coasters solved it.

http://www.audiopoints.com has brass coupling disks.