I think we have different definitions of boom/bust. Bradford, if he avoids injuries, is a solid starting QB. Vick had a bunch of good years. Ryan is a solid QB. Same for Stafford. I think of bust as Tim Couch, Ryan Leaf, Jamarcus Russell. I sort of see Manziel being similar to Vick, capable of really good or really bad but on the field, or never seeing the field because he acts like a ********(Leaf), is lazy(Russell) or just can't grasp the offensive scheme(Tebowish).