One thing everyone agrees on apart from Rooster, Leonard's prime from was from around 1979 to 1982. The thing which people will tend to disagree on, exactly when he was at his absolute peak during that time period. The second Duran fight to the Finch fight IMO.
In all seriousness I think Duran 1 he may have lost the fight but they both were in phenomenal condition and at least physically Leonard was at his peak