Same AirPods, better sound, and better noise cancellation?! Makes no sense and you should know. Noise cancellation works even if not paired to any device, so that’s easy to verify.
Since it’s the AirPods decoding the song file and producing the sound in both cases, then if both devices are sending the same file for playback, there is no technical difference.
Try a blind test! Tell a friend to hide both devices from you, randomly connect them one at the time a you would be guessing which one is playing. Let us know the results, but no cheating!