It's dead even, Allen and Mayfield. I picked Allen, largely because Mayfield's off the field issues trouble me. I think Mayfield might be more ready to play in some respects (anticipation, play-making ability and accuracy). I think Allen has a higher upside and is more comfortable in a pro system. Allen's floor is Hackenberg. Mayfield's floor is Manziel. Neither are appealing. Allen's ceiling is limitless, and Mayfield's ceiling is probably somewhere in between Brees and Russell Wilson - maybe Fran Tarkenton is the best comparison. So the upside is there for both players. I just went with Allen because of his incredible physical skills. I don't see him as Jamarcus Russell - he's got a different makeup. He's more like Hackenberg, great kid, good intangibles and work ethic, etc. He just has to be able to put it all together and become a more accurate thrower of the football. Hackenberg couldn't get there, at least not yet. Mayfield is already pretty accurate and throws with pretty good anticipation. It would be a tough call.
If Rosen is there, I think they should take him. He's smart and can do it all. His upside to me is Aaron Rodgers without the same scrambling ability. But he has that type of arm, flawless mechanics, and intelligence. His floor is, I don't know who - I hear Jeff George and Jay Cutler a lot, so we'll go with that.