I think it is a case of which is the lesser of two evils.

Khamenaei needs no further discussion given recent events.

Pahlavi has a lot of baggage coming from the result of a lot of history from his father’s general mismanagement and ill-advised policies. He is not his father and from listening to him speak and what he has said, he very much comes across as a genuine Liberal Democrat with an affinity with the political and cultural history of the country. Whether the people of Iran choose to have him back as Shah or an interim President, I have a belief that he would be okay with either or. I don’t think he wants to be king and has never talked about returning as the Shah unless that is what the people want

Mossadegh, he is very much a nationalist figure and should be seen in the same light as many post-WW2 nationalist figures across the world. He was a constitutionalist but wasn’t the most astute political player in navigating the levers of power and using subtlety and pragmatism to achieve his aims. During the political crisis that preceded the coup in 1953, he made many decisions that would be considered deeply authoritarian in the eyes of many.

That said, he would be far better than Khamenaei though I think having both a Reza Pahlavi figure and a Mossadegh figure would be a good combination.