At Equifax we had the Tooling "Holy War" of Agile software and ultimately chose to preserve the right of our Agile teams to work the way that they preferred:
1. .NET folks insisted on TFS with the Visual Studio IDE integration.
2. Jira teams had learned the Greenhopper bolt-on to the bug tracker.
3. Rally users preferred the more natural alignment with Scaled Agile and business-friendly usability.
Software vendors were reluctant to support our strategy with their pricing models, but options were found. Our lightning story highlights the good, bad, and the ugly from going down this path with a surprising twist thrown in.