Clearly, for you.

I've read the same opinions about Opus and yet it was gpt 5.5 pro via api tackling the hardest problems.

I have used now k3 for 3 days and it has consistently tackled difficult problems sol max could not (orientation optimization algorithms of random 2d shapes on a rectangle for glass cutting).

I have also other beefs with Anthropic models which have been getting smarter and more capable since 4.6, but increasingly worse at acting as assistants, they just want to "do" stuff their own way and ignore instructions often (even simple ones like not to commit, let alone complex ones).