Product review (5 stars): Works great!
Bought for a 2008 GE front load washer.  Didn't have problems with walking, just lots of vibration transmitted through the floor.  After quick installation (2 person job), vibration through the floor has greatly reduced!  I'm definitely no longer concerned about long term damage to the flooring structure, and the washer actually seems much more stable during the high spin cycles.  Very happy with these!

NOTE: To install these, you need access to the back of the washer from the sides (or back).  Once you have feet on the pads, the washer definitely will not slide.  If you have the washer in a tight space and need to slide it out, buy the regular Silent Feet Anti-Vibration (green package).  That includes two pads with an "easy-slide" bottom for sliding the washer back in place before you install the front pads.  From their website:

Silent Feet:
- Best for small laundry rooms with limited space to access behind your washer and dryer.
- Fastest and easiest installation.
- Prevents mild to moderate appliance movement (walking).
- Best if you have a work-surface or counter over your washer and dryer.
- Best for carpet, concrete, rough stone and natural tile floors.

Anti-Walk Silent Feet: Buy Now
- Prevents moderate to severe appliance movement (walking).
- Best if you have space to access behind your washer and dryer.
- Best for stackable washing machines and dryers.
- Best for smooth & high gloss floors like gloss tile, polished stone, wood and vinyl.