How do Vito Corleone's competitors describe his personality?
As you used the word "competitors" in your question, I suggest that you read Thomas J. Ferraro's essay (the first link below) which reads The Godfather in the context of American capitalism and argues that "the ethos of ethnicity is by no means anachronistic in late capitalism". Ferraro sees the tightly-knit Corleone family and Don Vito's constant appeal to ethnic values and group solidarity as facilitating enterprise and thus as "the primary motors of capitalism, not its antithesis". Its competitors recognize that family honor coupled with self-interest constitutes a decisive trait of Vito's personality. His preference to employ family members in his underground crime activities has proved profitable in economic terms. According to Ferraro, this double characterization in terms of kinship and economy are apparent from the wedding scene when Vito is introduced as both the godfather and the chief executive officer and the rest of the family members follow this double characterization (role in the family and role in the business).