The strongest arguments prove nothing so long as the conclusions are not verified by experience . . .
I had a great manager years ago who knew the value of testing, and observed that I was particularly good at getting other people's programs to fail. He gave me a copy of Peopleware so that I might read the chapter on the Black Team, IBM's infamous testers of the 1960s who would revel in making developers' software fail. To the uninitiated (or software development managers), the chapter reads like a story about a bunch of jerks who nowadays would be accused of subjecting software to unrealistic tests and wasting the company's resources. My contrarian opinion is formed by an excerpt from near the end of the chapter that reads, "Needless to say, the company was delighted. Every defect the team found was one that the customers wouldn't find." You do not have software customers. Your customers are the users of your network and its applications. As you complete your IPv6 transition activities, remember the importance of verifying the results. If you're one of those people concerned about the happiness of others, think of all the users who will enjoy high-quality network services and capabilities. If you're the selfish type, think of all the trouble tickets and 3 a.m. phone calls you won't get, if you verify that your transition activities got done right the first time. It's a win-win either way.