Repent or else, that type of street preaching irks me. People present it as an ultimatum of two options, but it really isn't like that. They are already condemned, the choice is salvation. I understand that they can choose to stay condemned, but in actuality it isn't an ultimatum of force but mercy. It isn't tyrannical, "Love me, or else." Its coming from a place of not wanting them to be condemned, where as the repent or else signs come from a place of condemnation.
I don't know if I made the distinction clear enough, but one is set as an ultimatum where you have two options, and the ultimatum makes it seem like God is forcing you to love Him (i.e, tyranny). Where as the reality is that they are already condemned and God desires to save them from this condemnation and wants reconciliation. It isn't an ultimatum of tyranny but love.
Its as if a man is hanging off a cliff and you throw him a rope. Can we say there is an ultimatum? Sure. Can we say that the ultimatum is condemning, such as "Repent or else!"? No, we clearly see someone who is helpless and yet salvation has been offered to them in love and kindness. It isn't a matter of "If you don't grab the rope, I am going to kick you off the cliff", but rather, "Please grab the rope!"
2 Peter 3:9King James Version (KJV)
9 The Lord is not slack concerning his promise, as some men count slackness; but is longsuffering to us-ward, not willing that any should perish, but that all should come to repentance.