Source control, and work item tracking, from user experience, it is very easy to relate code versions with work items, and to track your changes easily from multiple interfaces "Visual Studio, TFS web browser."
Also, the API for managing TFS programmatically is very powerful, you can listen on work items changes by TFS events.
Also, you can easily create, update, and delete work-items from the code itself.
In addition, you can extend Visual Studio IDE by adding extensions that you can use with TFS API, to extend the work items module.
Microsoft provide a full BI solution for reporting , and analyze the TFS data in order to bring powerful reports for top management
Recent changes/upgrades that were made:
-New software processes was added.
-Ability to create custom dashboards for each team project on TFS web browser.
-Ability to integrate with Microsoft enterprise project management tool, which covers the gap between software process, and project management tasks
We implemented the scrum process in our company, and we used TFS as the main tool to manage that process.
We upgraded to TFS 2017, which has a lot of features for SCRUM process that can be managed from a web browser.
Yes, sometimes we feel that it need more CPU, and RAMs on TFS server, either we implemented the hardware with the product minimum requirements.
No, it is very easy to scale it up.
I haven't needed to contact them.
I used before IBM Clear Quest, which had a very bad interface, was very expensive as they price per user, was very hard to modify screens, no flexibility to extend, and by the way it can only be integrated with IBM Clear Case source control.
TFS also is one license for multiple products "source control, work item, build management, reports" also it integrates easily with other products, by its powerful API.
Also it is not easy to find an IBM CQ , or an IBM CC consultant, while it is easier to find a TFS consultant.
It is very straightforward.
Excellent, especially if you have an enterprise license agreement with Microsoft.
See my prior answer about previous solutions used.
Try to bring the latest version, TFS 2017.