You've gotta keep in mind their product is not the day to day engineering work while you're engaged with Pivotal, but the transformation of your team.
If they're successful, you're left with a team who adheres to or even enjoys the rules and rituals laid down by Pivotal, and you end up with that team I described who can "kinda-sorta mostly get anything done... eventually... with the help of a few external vendors..." From a business perspective, this isn't a terrible place to be.
If they aren't successful, oops, your entire team churned during your engagement with Pivotal, but don't worry -- they're happy to help out with your hiring processes.