I agree with chitown. The vibes ARE great for dry. They hook a lot in dry, but it's good hook. They retain energy so well. It's hard to explain to most players that it's a dry lane ball that hooks a lot. The thing is, it doesn't hit like a pumpkin on the dry when other stuff would.
There are also plenty of medium conditions where either Vibe is useful, though. Even still, they are DRY lane balls useable on medium conditions.
I think the measure of a ball is probably how often you see it thrown on TV finals by staff guys/free agents. The lines you see thrown from Hammer are Vibes (Blue almost exclusively) and Widows (seems like all of them).