[mothered]

They do work (to some degree), some better than others.

Here's a recent article which contains rather Informative reviews.

Although it seems that depending on your house and the houses around you, it could be a issue. Just too many variables to figure out when setting up one of these.

You're certainly correct.

The reviews document their advantages at the "maximum" coverage/speed as per factory specs. Your equipment, location and obstacles around you all play a major role In their performance.