In an issue of Justice League, Wonder Woman states that she thinks she is faster because she is a trained warrior and her actions are in her muscle memory. Batman agrees, asking, "who's faster, Usain Bolt or Bruce Lee?" I say that this is complete BS. Superman is a master of Kryptonian martial arts, has fought for 1000+ years, and I've even heard that he's beaten Batman while powerless. It's often stated that it takes about 10,000 hours to become an expert at a skill. Superman has fought for many times that amount. He's had plenty of time to adapt and perfect a fighting style for his powerset. That's not even considering the fact that his super senses, intelligence, and speed should enable him to master anything in even less time. All in all, I think his reflexes are often underrated in both the comics and on the battle forums.