Luck isnt exactly the word to use for the last week or two. Google Forums got flooded with tens of messages about faulty speakerphone. According to users, when on a speakerphone call, the other person will hear an echo, squealing and other weird noises. One of the owners suggested to Mute your mic when on a phonecall, but is this really the solution?
Browsing through the Issue Tracker of Android Open Source Project you can clearly see a pattern – when you turn on the speakerphone, the caller can hear himself echo and the returning sound is nowhere near pleasant. Owners of Nexus 6 have no problem though – their side of the call is perfectly fine.
So Nexus 6 who do a lot of speakerphone calls might want to postpone that Nougat 7.1.1 update until the issue is resolved.