All great QB's flogged around for their first few years. Elway was considered the next coming of Christ here, but was crucified terribly when he couldn't win the Super Bowl. Of course coaching plays a big part and Dan Reeves wouldn't let Elway be Elway: Shanahan did and look what happened 2 Super Bowl wins. For the consistancy I would rather have Montana or Marino (great supporting cast) than Elway.
As for Young or Leinhart: I'll take door 3: Jay Cutler: very reminiscent of Elway.
But only time will tell...