I just don't see how Hashirama could be overrated.
- He possesses regeneration-abilities on Tsunade's level, meaning that Tsunade's most impressive ability is only one under many of Hashirama's powers.
- He possesses powerful Genjutsu that not even Hiruzen could break.
- He's capable of using Mokuton, the - according to Masashi's own words - most versatile technique there is, capable of changing the entire landscape and almost owning five Kage at once.
- Thanks to Mokuton he can use Moku Bunshin, the most powerful form of Bunshin that will not disappear after being hurt.
- He was capable of not just suppressing but controlling Bijuu, keeping them like pets.
Keep in mind that those stunning abilities are only a part of his arsenal and we still don't know the full extent of his powers. Yet those few things already grant him a position as a top tier Shinobi.
Just look how coveted his genes are: They reduce Koto Amatsukami's ten-years-interval to only a few hours and enable people to use (a perfect) Izanagi. His mere DNA must be suppressed with Chakra, since otherwise it takes over the user's body. It's just ridiculous.Hashirama's hype is
definitely justified.