Meh......I think the majority of iranians think he has no legitimacy.
The most he has accomplished was setting up his own website. http://www.rezapahlavi.org/
Unlike the Shah's son, most Iranians still have family in Iran.
It's risky be too cozy with the Phalavi's. However many of the exiles still have warm and fuzzies with the Mosadegh period.
But almost all Iranians are nationalist by nature. One of my Persian buddies tells me that Iranians are like Texans, but with 4,000 years of history.
Well I always see him on Iranian channels talking about how much he supports democracy etc... and that he doesn't want Iran to ever to go back to the absolute monarchy days blah blah
He seems genuine to me. Many Iranians actually like him as a person, both inside and outside the country (mostly for the way he carries himself and the things he says). He seems to be a humble guy. LA Iranians often see him shopping in grocery stores even though his family has billions.
That said, nobody in Iran would ever in a million years allow the monarchy back in, no matter how power-less the monarchy would be. I can see him running as a politician one day (that's if the status quo changes obviously). He would have to ramp up the sweet talk a lot more if he wants to ever please the masses. Iranians have become allergic to the whole monarchy thing.