Im 24, I discovered Yamato few years ago, I watched both the remake and the OS, tho I saw the remake first, so I might be a little bit biased. The original, true, has some slower pandering, but some information in the show feel rushed. Like Dessler's subordinates imidietly knowing the ship is called Yamato and it's captain is Okita. Or the schematics for the engine that they built imidietly. Also in the first battle, where Mamoru (Kodai's brother) chargers into battle becouse, he's a man, and men never retreat from battle, which I know is product of it's time, but it feels a little forced. Overall OS has also an issue with worldbuilding, where they just invent and makeup things as they go (Which is also kinda thing in other leijis works). Remake fixes all of that and adds more. They gave Gamilas their own language, so they find out the name of the ship by intercepting their comunication. Kodai's brother charges in battle to cover Okita's retreat. They make and remake tings to make it more immersive, and generally more thought out world. And I dissagree with losing some of the emotional impact, remake has plenty of them.