It's so obvious his happy persona is fake, even the fans say that.
I personally like him more than others, I think he is cool person irl, and it's actually good that he is hiding his true self from the fans. Cs armys need to know everything about them, they will crawl through any hole to find out every little piece of their life. So he is quite smart saving himself only for his close people. If you always pretend bright sunshine without any mood changes people have nothing to discuss about you. He also doesn't really shares so much personal information about his feelings, for fans everyrhing always "fine". If I would be under microscope 24/7 I would do the same.
I think in real life he's closer to Suga, definitely more manly and serious. And if you remember in 2013 he was much more masculine, diffrent from now, I think it's closer to his true persona.
While Suga doesnt care and just being himself. They are my two favorite , I also think they both are not bad people.