I'll second the objection to the word 'hindsight.' Also, the '20/20' is obviously not applicable either since there doesn't seem to be a consensus on who would have been better if we had had a choice. Even so, please remember that even if, 10 years from now, Francis proves to have been worse than Davis, Elton Brand, and Lamar Odom, he was still a free gift! He was worth well more than what we paid for him. So it doesn't matter if he's the best in the league or not; he was a major building block that we managed to pick up cheap.
I'd take Baron Davis, mainly because of the migraine problem, but also because I think Davis has a better overall attitude than Steve.
I would take Francis. He is a better scorer, better rebounder, and a much better shooter. I think that his ear problems will go away and he will have a great season this year.
Migraine problems aside... I think I take Steve Francis. Before that draft, I thought Davis was definitely the best PG except for his injury right before the draft. In college, Davis' explosiveness was unmatched. However, Steve has the potential to have a very strong all-around game at PG. I just don't think Baron Davis offers quite as much as Stevie does.
I think Francis wants to prove something this upcoming season, and he will show what he's really worth. I have this gut feeling that Francis is going to be recognized as the best PG in the league alongside Kidd. There will always be the argument of team player vs. scoring.
