I'll say after having it run for a few hours that I still don't feel it matches even Sonnet. It still does a lot of back and forth that feels dumb, but it's possible this is in effect Anthropic tricking us by hiding the full reasoning traces - who knows what Sonnet still sounds like if you were to see the whole thing.
I haven't tried K3 yet but my experience with older Kimi models was exactly this, that they'd spin for a whole chunk of time with a lot of back and forth thinking.
But some of this might still be something that gets sorted out with finding the right parameters etc on the serving side.
EDIT: Just switched my Kimi-CLI session to K3 and resumed my ongoing /goal... Will be interesting to see if I notice a difference.