Forte is the easy choice.
Why? Just reflect on the reason why Eddie Lacy fell to the 61st pick. He was the unanimous top RB in the 2013 draft yet 3 other backs were taken ahead of him. In terms of talent, Lacy was a surefire 1st rounder. So why the drop? Why did Green Bay trade down and then only reluctantly draft him? Injuries.
Granted, Lacy has generally played through pain, but throughout his career he's constantly appearing on injury reports (hamstrings, etc). There's also a widely held belief that the toe Lacy had surgery on a while back will only last so long before it gives out and when it does Lacy will be done.
And this is for a high workload RB with a very physical style of play.
I think Lacy is a stud and if he plays 16 games he'll be a top 5 RB. But I think the injury risk and the potential for a sophomore slump make him one of the riskiest picks in the draft. Teams that win fantasy championships almost always hit on their first two picks.
You can take Lacy, but just know that his risk is high. If you have Lacy, I would avoid any other risky RBs until you get to like your 5th or 6th RB, and if I were to draft Lacy I would make sure to have a "money in the bank" 3rd RB, a guy like say Frank Gore, Joique Bell or maybe Reshad Jennings. Someone that can help soften the blow if Lacy gets hurt.
Meanwhile, Forte had more points than Lacy did last year and it wasn't close (251 vs. 198).
It stands to reason that Chicago's offense will be even better in 2014. Jay Cutler has looked sensational this summer and the Bears O-line is quickly becoming one of the better groups in the league. Chicago is a sleeper candidate to finish as the NFC's top offense.
Forte is old by RB standards, but hasn't slowed down and because he missed the playoffs last year, his rushing numbers were kept to a moderate number so I'm not expecting him to be "tired" this year due to a high workload in 2013. He's only gone over 300 carries once ever, as a rookie in 2008. Even though he's 29, he only has 1553 career carries (259 per season). Last year he stayed under 300 carries and added 74 catches, which to me is an ideal ratio. The reason for Forte's skyrocketing fantasy value was that his reception totals basically doubled in Trestman's offense.
Forte has only missed 4 out of 96 NFL games.
My only knock on Forte is that he's not the greatest RB for racking up TDs. Last year he had 12 total TDs which is well above his career average of 7.8. He will probably decline some in the TD department this year, but I still expect him to be a stone cold lock for the top 5 RB group.
I think Forte has a good chance to beat out a healthy Lacy, and Lacy's health is much more of a question mark. But mostly, I would draft Forte because he wouldn't stress me out, he's money in the bank. And he wouldn't force me to draft a #2 caliber RB as my #3 guy in round 5 like Lacy would.
I like Lacy a lot and would happily draft him 5th, but I would much rather pick one spot sooner and get Forte.