I've done a side to side comparison recording my stereo with new vs old capsules in the same old bodies into the same recording chain. I heard a difference, not night and day, but I could tell the samples apart blindly (I'd post them, but I deleted them). New vs old bodies, I don't know if there are any audible differences as I never tried that. But I would suspect, like SmokingJoe, that the capsules make most if not all of the audible difference.
I've only experienced cell phone noise once, but that one time was enough to ruin the song.