Well I don’t know how a hyperdrive is slow, but a hyperdrive is a hyperdrive.
And if Han has it, he would use it, in a situation like that.
He didn’t even try.
The only explanation for that, that there was no backup hyperdrive. Or he is stupid, but I would dismiss that probability.
It’s obvious, Han’s a player. He deliberately took it slow getting to Bespin so he could could have some alone time with Leia.