Keane was a bang average midfielder who had a will to win.
In terms of footballing ability and temperament I see no difference to Joey Barton (given, Barton had more off-field misdemeanours) Limited ability, all mouth and more famous for reckless tackles and confrontation than contribution to football.
The only difference I see between the 2 is that one played in red. Had Keane played for Everton/Villa/Spurs for the same period he would be viewed as nothing more than a thug.
People in the media mentioning Keane in the same breath as Vieira says all you need to know about the dinosaurs who get column inches.