TFS/VSTS Best Practice Analyzer - Success Stories ... BPA Passion!
Using the latest drop of the TFS BPA tool, which will appear in the Power Tools one of these days, I was able to highlight and resolve two production implementation issues.
Case 1 ... TFS implementation which was apparently "ALL OK".

Why has no-one noticed that the disk space, hosting the TFS/WSS production databases has dwindled? Thanks BPA, the disk storage will now be upgraded "pro-actively", before we have a meltdown.
Case 2 - An implementation which had ongoing issues with reports not updating ... remnants of a disaster recovery exercise?!?
Thanks to BPA it was noticed that both the SPTimer and the TFSServerScheduling services were not operational ... incorrect credentials. Thanks BPA, may the services resume their rightful duties!
Conclusion
Using the BPA tool is as simple as point to server, run analysis, review analysis and fix it ... "FiFi (Find It Fix It)" comes to mind.
The simplicity for the operational environment, yet extensive analysis and feedback is what makes me so passionate about this tool!