Everyone who has had good or bad results should keep several things in mind. First, a hidden antenna will NEVER be able to reproduce the -db gain of an whip antenna without some type of built in amplifier or antenna booster. Secondly, the amp will also amplify noise equally well. Also keep in mind that even though you live in "XXXX" city and listen to their FM station, the actual antenna may be miles away from your location. My local Corpus Christi radio station's control center is less than 6 miles away from my house. The antenna from which they broadcast is over 30 miles away from my house. So when I use my Antenna Specialists hidden antenna at my home, I get bad reception. When I am 30 miles away in a town called Sinton, Tx, the signal is rock solid. Not because it works well, but because I am less than a mile from the actual 100,000 watt transmitter.
Every hidden antenna will be a compromise. It's just up to us to decide what we WANT to compromise........Looks or Signal.