Pretty late to the party with this reply, but I would generally agree with the sentiments above. It's a very steep drop in animation and narrative quality from the previous season.
That said, I really enjoyed the interactions between Saitama and King, definitely the highlight. There's a number of really good conversations they have.
As I understand it, the One Punch Man manga's story has written itself into an insane corner, so- part of the problem might be that they don't really have anywhere to go. Not with confidence, at least.