Truthfully not the biggest fan of itagaki's fights. I think this is intentional as a foil for Ippo's own development where as Itagaki is like god's favored child developing before our eyes.
Not to say he didn't put any effort, but there really do exist different classes of fighters, just look at Takamura. He can afford to be retarded in his fights due to his own talent and his own effort so seeing genius's in action easily overcoming odds isn't quite as fun as seeing every inch of Ippo's efforts drive him to a hard fought victory.