It's just as contentious. My dad will avoid restaurants that serve Pepsi because he prefers Coke so strongly.
The Pepsi bottler near my hometown is one of the few independent (not corporate owned ) left in the country. The owner was a real piece of work. He would send his employees to restaurants that serve only Coke, tell them to ask for a "Pepsi" and tell them to throw a fit when they received Coke. He would also take punitive action against employees that were seen drinking Coke in public. That's how deep some of this shit goes.
Back on topic, it appears that even Wonder Woman prefers Coke to Pepsi.