Product review (2 stars): amplify wobble during spin cycle
I bought these hoping that they would make it easier for me to pull the machines out to clean up the lint behind them.  Unfortunately, they amplified the wobble of my washing machine so I couldn't use them.

My top-load washing machine has a slight wobble during the spin cycle.  It's not that loud.  These feet amplified the wobble so much that the drum was banging against the sides of the washer.  I tried comparing using the feet and not using the feet a couple of times, checking that the machine was level.  Without the feet, the machine makes a "bumpbumpbump" sound.  With the feet, the machine vibrates wildly while making a "BANGBANGBANG" sound.

I have laminate floors over a concrete foundation.