#1 is Sam Darnold. Sub par coaching in college has limited his development from the 2016 season to the 2017 season. He is not the polished prospect that Rosen is, but he is a much better leader. You would like more of a finished project, but his learning curve, like Mahomes and Watson's, will be quick. He has talent and a great work ethic. Best QB in the class.
#2 is Josh Rosen. He is a little like Jay Cutler in that he has the intelligence and physical skills to be the guy, but his personality won't fit everywhere. I worry that he has never really had the struggle of Darnold/Mayfield/Allen to create the chip on his shoulder. I don't know what he is willing to do to be great.
#3 is Baker Mayfield. I hate immaturity in my QBs, and that coupled with his lack of prototypical size gives him more ways to fail than Rosen and Darnold. That being said, his accuracy is awesome, and he has shown to be able and willing to push the ball down the field. I like his leadership on the field, but I worry about how he leads off of it.
#4 is Josh Allen. Rudolph is probably more likely to be an average QB than Allen, and Lamar Jackson is more athletic. What I like about Allen is that he has the highest ceiling of the three and if I am taking the 4th best QB to develop, I want the one with the highest ceiling. I have real concerns about his accuracy, and that can lead to bust. I don't believe that I would trade up for Allen, but of Jackson, Allen and Rudolph at 15, I would take Allen.
#5 is Lamar Jackson for me. Good athlete who needs work. Similar player to Marcus MAriota where I see the desire to make more plays from the pocket, but it may never develop into a natural trait. It is hard to change what has always enabled you to be successful when you are under duress.
#6 is Mason Rudolph. I do think Rudolph sticks in the league, and I would not have an issue if the Cardinals took him in round 2. But, I would never pay a premium price for vanilla ice cream, and that is how I view Rudolph. He may be an Andy Dalton type NFL player which is worth something, but not the #15 pick for me.