There is a clear benefit: you get to hear what they're saying, while without signing the NDA you won't. On the other hand, there's very little downside to sign

There is a clear benefit: you get to hear what they're saying, while without signing the NDA you won't. On the other hand, there's very little downside to signing an NDA. Sure, it'll prevent you from revealing the information. But without signing the NDA, you don't get access to the information in the first place, and just as unable to reveal the information.