Saw the film on Friday and quite enjoyed it. Yes, it's more about Borg and his growing up, his personality and his tennis but LaBoeouf does a fine job emulating Johhny Mac in his run  up to the Wimbledon match in 1980 around which the movie culminates.  It's not really a tennis movie it's a movie about two athletes who were viewed as polar opposites but who really had many things in common as a result of their upbringing.