McKinsey vs Bain Advice?

Hi all, 

I'm fortunate enough to have offers from Bain and McKinsey (both major offices, though the cities are different) 

I don't have a strong preference for one city over another, and want to focus primarily on career trajectory (both in terms of being promoted within the firm and comparing exits) and employment experience when making my decision. 

Would appreciate any insight you all can offer into any of these factors/the comparison. Thanks a lot!