Whats your criteria for good or bad?
Do you mean good for Zoro’s character? Well yeah, King is the strongest swordsman Zoro’s faced so of course beating him advances Zoro’s goal of becoming WSS.
Do you mean good for Powerscaling? Sure. Zoro has a bunch of powers he needs to learn and master now. From Enma to CoC to Ashura to maybe even an advamced fire ability or even Black Blade shit. All these can be improved upon DESPITE what you think of King’s strength. Zoro doesnt have to fight the strongest person in the world to improve on a skill or technique as we saw in Alabasta and Skypiea.
Do you mean good for plot progression? Well this depends on what the intention here is. If Oda eventually wants ALL the strawhats to go the roof then it will play out like Zoro vs Ryuma which was followed by the strawhats vs Oars. If Oda wants this to be Zoro’s last fight in the arc, Oda has the medicine Side effect plot mechanic to remove Zoro from the arc whether you believe King is strong or not.
Do you mean good visually? Of course. King looks very good in motion even without hybrid and the fact that he is 4 times Zoro’s size qnd has a sword easily the size of Zoro’s whole body means it will be interesting to see how Oda shows sword clashes here.
I mean, maybe you should be specific on what you consider good or bad