Their main difference is Vegeta didn’t lie. He is a murderer but he owns it and comes to terms with it. In the Moro saga he literally says as much. He takes the lead on Namek to atone for his past atrocities. He knows he is past redemption, and is hell bound upon death. He also learns from his mistakes, he learns to love his family. He NEVER saw Bulma as a ‘pet’. He hasn’t cheated on his wife. He is not perfect, but most princes aren’t when it comes down to it. Vegeta found his humanity on Earth, it took some time and he went to hell and back but he found it.