I'm meh on consistency. I think it's too hard to achieve in the NFL. Brady and the Patriots are the exception- the consistent winner. But I throw them out because it's not replicable. So consistency gets you guys like Brees, Rodgers, Roethlisberger, Rivers, Wilson...guys who can perform season after season without a much variation. They're worth a ton because they can get you close to the Super Bowl year in and year out.
However...they're pretty rare as well. And if you can't have a Hall of Famer behind center, I'll take a guy who's going to have an up and down career but the highs can take you all the way to the top. I think Allen can be that guy who can dominate when everything clicks for him. It won't be every season, probably, but he could have a Newton 2015 or Kaepernick 2013 or Flacco/Foles playoff run to win it all. That's good with me for now anyway.