In the end, we picked Planview LeanKit because of several reasons:
Aesthetics: The look was much more clean and professional.
Reporting: It was obvious from the start that we could use Planview LeanKit as a tool for improvement.
API: We needed to integrate the Kanban into our central systems and Planview LeanKit API was (and still is) a way to do it.
Card Headers: This sounds like a simple thing, but the headers above the titles fit our work perfectly and looked perfect, which helped the decision.