Happy consumers can be a simple general way to also refer to a happy audio enthusiast. To me they are very different, so I am not sure what point of the question is.. But to get more granular, an audio enthusiast is different because it is usually person who loves music first, and is passionate about equipment second. What that hifi equipment is can be a completely different discussion altogether. Hi-Fi is really it's own very obscure category..I have lots of friends who think the pursuit of hi end audio is silly, and I can understand why they think that, they would be categorized as a satisfied consumer. On the other hand, I can't fathom listening to music any other way than through hi end equipment; Bose, and Marantz and Denon, and Sony, etc to me are not hi-fi, they live in a completely different category, where happy/satisfied consumers live as well.
Audio enthusiast is someone who cares about detail in sound, and details build quality of equipment-and the fun associated with it..To me hi end audio is a small shop operation, not operated by a conglomerate in an effort to stay viable, often times hifi manufacturers are just a few equally passionate people who have the ability and have chosen to make hi end audio equipment (thank you for them!). Because they too love music like most of us here on the forums, and these are the people that understand that things CAN be better than commercial, mass market equipment.
I mean does the guy who owns Bose equipment know why a Black Gate Capacitor is better than what they use in Bose? Or how important circuit board design and layout is? Or Power supply-doubtfully. That doesn't mean he is stupid, just not interested. Does a guy who owns Sony CD player know that DAC inside is what makes a CD sound better or worse-doubtfully....I will say one thing, the guy listening to the commercial mass market equipment has one major advantage usually, not overpaying for this stuff they way we ALL do, and they still get the benefit of hearing music. Without the magic of course. : )