I ordered a pair of these and have had them in place for couple weeks. You can feel them working within hours. So far I love them. I have only noticed one slight problem on one of mine. The button to lock out all buttons will light up and be on but always goes off on it's own. Tried unplugging it and didn't help. Not sure if this will lead to future issues, but with the lifetime warranty I'm not worried. the other unit is perfect.