Francisco was my pick.
He's been extremely productive across the minor league ladder and in his small sample of major league games. His power is among the best in the game and he's still very young.
When compared to Grandal, Francisco grades out as likely younger at a higher level (as it will probably take him longer than a couple years to be where Francisco is now). Francisco also grades out as a much better bat, with both a higher ceiling and a higher floor.
Grandal grades out much higher defensively and across the spectrum of positional value, but that's tempered a bit by his level and lack of professional experience, especially considering his C position.
As to Frazier, Francisco grades out with better power and better minor league numbers at the same level against the same pitchers at the same time. (Which is just about the only way minor league players should be evaluated with pure numbers.) Francisco's BB rate, a topic of great concern and debate across Redszone, has improved each of the past three years. He still has a long way to go in that arena, but his power (likely a 500+ slugging percentage in the major leagues) can mask a lot of that. Too, he seems to be that odd guy that improves as he hits against better pitchers.
Positionally, it looks as if the Reds are going to keep Frazier either in LF, 1B, and occasionally at 3B, meaning Francisco actually gets a slight bump. Francisco, too, has a higher ceiling. Frazier does have the better defensive range and footwork, but Francisco's arm is tops.
The keys between the two of them is youth and production. Frazier is already 26 and hasn't sniffed the majors. Francisco's 23 and had a couple cups of coffee. Plus, Francisco's numbers-- especially in 2010-- have been better.
"You can learn little from victory. You can learn everything from defeat."
-- Christy Matthewson
"Show me a good loser and I'll show you an idiot."
-- Leo Durocher
Frazier is 24. He is approximately a year and 5 months older than Juan.
"You can't let praise or criticism get to you. It's a weakness to get caught up in either one."
I don't think Francisco can/will stick at third base and I know I'm not anywhere near alone in that belief. If he doesn't stick at third, where would he play? Left field is the only other possibility and for some reason, most don't see that being an experiment that would work.
"No matter how good you are, you're going to lose one-third of your games. No matter how bad you are you're going to win one-third of your games. It's the other third that makes the difference." ~Tommy Lasorda
He probably can also play first base. Or can be a DH. Has the bat for both of those spots.
As for third base, he has the advantage of a great throwing arm which can compensate if he doesn't have cat-like moves.
JF has a true power bat. They will find a position for him. He'll be hitting homers for the Reds or someone else.
Francisco's ticket is not in the NL.
His true power bat also comes with what currently projects to be extremely on-base challenged.
Wily Mo Pena is an apt comparison, at this point in time.
You are aware though, that national prospect-related experts may not be as knowledgeable on all aspects of the Reds system as some local prospect oriented fans, right? So if the prospect rankings reflected more of the specific knowledge of the board, rather than the general zeal of the board, they could concievably influence national rankings, instead of mirror them.