A system and method for selectable sampling of a received RF input spectrum copies the input signal into a set of equivalent input spectra, one for each of a set of parallel sampling paths. The sampled input spectra are converted to a common sampling rate (e.g., baseband I/Q stream) and demodulated into a digital signal for each current time window of a sequence of time windows based on the common rate and corresponding to the receiver output stream. For each current time window, evaluation blocks store the demodulated signals to memory and evaluate the signals for signal quality, distortion, and/or receiver sensitivity based on figures of merit (FOM) determined by the waveform. The highest quality demodulated signal is selected, retrieved from memory, and appended to the digital output stream, providing low distortion demodulated digital output based on the RF input signal in real time or near real time.