SA is consistent yes, but also is older than the other two RBs, has the superbowl hangover to deal with, and is a bit overrated in my view. He was the #2 or 3 overall last year, but he's never gonna perform like that again. Reminds me a bit like Peyton last year where everyone was taking him early, yet he never even got close to his production from the year prior.
Also keep in mind my league is a PPR league... LT catches alot of balls, but LJ racks up lots of TDs... its quite a dilemna.