My belief is that almost any QB can be successful. A lot depends on the coaching staff to put said QB in the right system while developing him along the way.
Andy Reid is the best in the business at this, in my opinion. McNabb, AJ Feely, Kolb, Vick, Foles, Alex Smith...he just plain gets the best out of his QBs.
I'd trust Jackson with him and only him. Other than that scenario, I'll believe Lamar can hack it when I see it.