Franklin is a favorite of Matt Waldman. I think Franklin is alright- strikes me as a perfectly average NFL RB. More of a competent RB than a "wow did you see that" RB. Think Mo Morris.
Montee Ball is a lot like Mark Ingram. Tough, smart, polished, slow, good vision, nose for the endzone, benefited from awesome run blocking. I was a big fan of Ingram in 2011. Unfortunately, Ingram's been one of my bigger whiffs. He's been a big disappointment so far despite playing for a very good offense.
I wouldn't hate getting either one, but there are many others who excite me more. Of the two, I think I'd prefer Ball. I think he'd fit our power running game very well. That plus I have some emotional attachment to that 2011 Wisconsin team, and it would be pretty amazing to see Wilson handing off to Ball once again.