I think Allen is the long term solution. Like you said, pretty raw to start and had quite a bit of improvement in year 2 with better players around him. Regarding Barkley, I don't think he's very good but I don't expect the Bills to make a change there. Most backups look like crap when entering mid game, those with less familiarity look even worse. For that reason alone, I think they keep him. But I wouldn't be opposed to an upgrade if available.