A super-regen "radio" overloads easily by strong local stations.
Its bandwidth is either too wide or too narrow since it has only a single tuned LC instead of many LCs and crystal filters in a real radio.
It squegs at an ultrasonic frequency that beats with the 19kHz pilot of an FM stereo radio station and beats with the 23kHz to 53kHz stereo subcarrier. Its squegging oscillaton also beats with 67kHz SCA restaurant music and digital identification subcarriers. The beats are a hum, a squeal or both.
It has an AM detector that receives very distorted FM by tuning to one side of an FM signal and letting it slope-detect. Since it is an AM detector then it picks up all kinds of interference.
It causes interference to other radios since it oscillates at the frequency it is receiving.