An electronic device may include finger biometric sensing pixels and a processor capable of cooperating with the finger biometric sensing pixels to generate a series of finger images at a progressively slower capture rate as a finger settling increases over time from initial placement of a user's finger adjacent the finger biometric sensing pixels. The processor may also be capable of cooperating with the finger biometric sensing pixels to determine a quality factor for each image in the series thereof, and select at least one image from the series thereof for matching and based upon the quality factor.