I'm Jonesing to get a pair of HD600's and want some opinions about the build quality or anything else I should know about the new production ones vs the older ones. I hear the new ones don't come with the case, which is a bummer, but not a deal breaker. The build quality on the other hand is important, and I'd like some opinions. I'm not overly concerned about looking cheap, but about actual quality as to product life and quality. I'm seeing used older style ones being bid up to the prices of the new ones. Already have the Massdrop 6xxx, so lets not go there please.