Would Mousavi be worse than Amadinejad?

It's a fair question. The neocons are arguing that Mousavi would be a worse leader for Iran than Amadinejad. But then, the neocons also want Israel to bomb Iran. Crazy-talking Amadinejad gives them justification to do it. Mousavi would make it harder for them to do that, if he did indeed institute the reforms he ran on in the election. Consider this, from Mousavi's page on Wikipedia:

Mir-Hossein Mousavi

[...] Goals for presidential term

Mousavi has on numerous occasions indicated his wish to change the constitution in order to remove the existing ban on the private ownership of television stations (currently all Iranian television stations are state-owned), as well as transfer the control of the law-enforcement forces to the President (so that they represent the people, since the people directly elect the President through popular vote) from the Supreme Leader.[10] He has said that "the issue of non-compliance with the Iranian rules and regulations is the biggest problem that the country is currently faced with" and that he wishes to put in place ways to enforce the laws further,[11] and that it is also important to bring an end to keeping people in the dark about government matters [...]

I recommend reading the whole thing. Unlike Amadinejad, Mousavi is not a holocaust denier, and has actually condemned the holocaust. While the kind of government he represents is not the kind I personally would want to embrace, it would seem to be more flexible and more open, perhaps not just like a Western democracy, but still more democratic than the current regime is. If his campaign promises can be believed. If they can, then he might be the best we can hope for in Iran's situation.

To be fair to the neocons, I believe Iran's nuclear program began while Mousavi was Prime Minister in the 1980s. He has stated that he believes nuclear power to be Iran's right to have. The Neocons claim Mousavi would continue the program just like Amadinejad is doing, but he would be quieter about it.

But consider this: Pakistan, a Muslim nation, already has nuclear weapons. It's likely, some would say inevitable, that other Muslim nations will achieve this capability as well. What are we going to do, bomb them all into oblivion? No. It's not gonna happen. So:

Which would you rather have; a nuclear Iran lead by fascist Armageddon-talking Amadinejad, or a nuclear Iran lead by a more moderate, open and accountable Mousavi? If he is indeed those things?

Those might be the good questions to ask. But at this point, it remains to be seen if he and his controversial wife, Zahra Rahnavard, will even physically survive the Iranian regime's brutal response to the challenge against it, or if they will die as martyrs.