For me the biggest differentiator is having a growth mindset. This doesn't just mean they want to make an impact and improve as a PM. For me it comes down to three things:
There is definitely a fine line here. Every decision cannot be data driven and will likely be informed to some extent BUT part of the excitment of product management is leaning on that intuition. In some cases, you will have data to back up your assumptions and in others you will not. Every situation is going to be different and you'll have to become an educated risk taker. Leaning on previous experiences or patterns you've seen somewhere else.
The two disciplines are very different, despite some intersections on go-to-market, outbound communications, and occasional blurred lines between the roles in some companies regarding strategy and customer requirements. Early on in my career I had the opportunity to simultaneously work in both functions and experience them. Product Management has very broad scope and deals directly with technology. Ultimately, for me, building (or fixing) products felt most rewarding. :)