Good points. And I think that O'Donnell and Maddox were our "Romo/Rivers/Flacco". At the time, I was hopeful that Maddox would be our "Kurt Warner" - and he very well may have been - if it weren't for that paralysis-inducing injury. He was never the same after that.
I also wonder about RGIII. He could continue to get better (like Ben, Rogers, Brady) or he could be a flash-in-the-pan like Newton appears to be. What a massive year-over-year change he's turned out to be.
I think the biggest difference between RGIII and Newton is between the ears. Newton appears to be a tad Vince Yong-ish.