There's always an inherent risk to 'best times to post' reports - with the most critical being that generic best times don't relate to your specific audience and their habits. The only true way to know what times are best for you to post is to study your own analytics, test different post times, then study again, till you find what works.
But that said, there is still value in using generic best times as a guide, particularly as a means to narrow your test pool. This is particularly relevant when starting out - if you start with the generic best times, you may be closer to finding your optimum posting time in the beginning, which can help deliver better results faster, while you're testing.
The team at CoSchedule also recognize that finding the mythical 'best' time for all can be challenging - so rather than coming up with a single survey report, they've actually collated the results of 20 'best times' guides in order to formulate a more comprehensive, inclusive report on best posting times.