I think at this stage in his career he can be a effective role player. He doesnt have the quickness anymore to be an effective starting back in this league. However he can still run with power, pick up the blitz and catch a few passes out of the backfield.
Alot of good stuff has come out about Randle early in camp, and it looks like he has the early lead. McFadden when/if he is gets healthy offers us alot as a 3rd down back. But with the term "dirty yards" thrown around during the offseason, I dont think we have that back. I think that is where Jackson still has capabilities. Let me ask you this, in a critical 3rd and one situation, would you rather have an untested HB or would you rather have a player like Jackson that still has the power to make that play, and knows exactly what he has to do and where he has to go to get to that marker and move those chains