Ask HN: A strong product vs. a strong culture which one would you prefer?

A bit of background, I currently have two competing offers to join 2 YC companies (both are in different domains). I've talked to founders from both companies and found both of them to be smart and ambitious.

A major difference that I found among the two companies was that the first company (Company A) has a really strong product but the company's culture seems not so much strong. The other company's (Company B) product seems to have changed very little in the past two years and its product seems neither technologically interesting nor highly appealing to the user. Despite of this, Company B has a better culture (at least that's what I found from the day I spent there).

Now, that I have made up my mind to join Company A over Company B, I am interested to know which of the companies would other HN readers pick.