Its only worth it if you hit on it, obviously. Then almost any comp gives the juice that's worth the squeeze. Risk/reward ratio is high in the scenario of moving up to do it. You REALLY need to love a kid to get the consensus necessary internally to make the play. It could very well be that Minnesota does not feel strongly enough about any of these guys to consider it. All of these 'rumors' can be complete horseshit. And even IF they feel that way about a certain candidate, they still might not be able to pull it off. I think things would need to fall a certain way and even then, its not like the Vikings are operating in a vacuum.....other teams could feel the same and have slightly more to offer.
The odds are against it. But the odds were also 99.8% that Minnesota was going to lose the Buffalo game. Shit can happen.