Sounds like an argument I'd want to avoid
I probably fall more on the formal side when it comes to calling people doctors. I agree with others that there's nothing inherently pretentious about the title.
To me, obtaining a doctorate requires an enormous amount of work, talent, and specialization within a set of historical/cultural institutions and the doctor title is representative of that. It doesn't mean that a doctor is a better person than another, but the title recognizes the dedication and expertise of that person. I'll be proud to be called a doctor after my degree is complete because I know what it takes to get.
It seems to me that in the US (and this is just my perception) is that we're eager to dismiss anything that appears like a class system. We fought a revolution over it, after all. Still, I'm fond of the titles for the reasons I state above. And until I can convince people to call me "master" (maybe magister? sensei?), I'll have to wait for my PhD to check the Dr box on my warranty cards, to which I really do look forward