It's fine to review provided references. It's also good to review published recommendations on LinkedIn or other venues of reputation arbitration. They're better than nothing, and often reflect reality, though to varying extents. Because everyone has gotten into the game of reputation management, you have to work harder to surface truth.
That's why the most compelling, informative and necessary references are ones you source yourself. They tend to be unpolished, less biased and reveal the nuances that make or break success.
Considering a new hire? Do the hard work of talking to a cross-section of people the candidate worked with -- not just the ones provided. Considering working with a new company and boss? Talk to current and former clients, employees, customers and partners. Considering hiring an agency? Talk not only to happy clients, but former ones and agency employees. You get the idea: perform your own 360-degree, independent reference reviews.
Acquiring independent references takes a lot of work. But it is the fastest way to get unbiased facts and make a confident decision.
Many will read this and say I've stated the obvious. That may be true, but it's worth stating again, because I frequently see people in all the aforementioned situations -- on the verge of a deep professional relationship -- ready to commit without the scrutiny of multiple independent references, personally sourced.