While the AmPlug has proved to be staple in my practicing arsenal, it suffers from its less than ideal build quality -- it had to be nursed back together by tape and rubber-bands after only a few months of ownership.
Because that time is spent in total stress, the amount and the quality they actually do contribute once arriving at the work site, suffers tremendously because most employees feel that they have already put in a full work day just by commuting to work.