dotcom-monitor LoadView is great for testing our ability to handle large amounts of visitors and their interactions with our site. It's also great at testing more complex interactions. For us, it's been invaluable for preparing for big events like class registration and wide-scale virtual events. It doesn't work as a CI tool but they do offer other products to serve that purpose.
Visual Studio Test Professional is best for .NET and C# based development, which is what 90% of our developers and projects do. It is an integral part of the CI/CD pipeline for our custom made Enterprise resource planning tool. It also works very well with Azure providing seamless integration to way more functionality.
Visual Studio Test Professional's overall usability is extremely high quality. It is extremely functional and like all Microsoft products has a user interface that is well designed and is extremely user friendly. Any functionality which I looked for, I was able to either understand immediately or find a user guide online.
My team has always been able to troubleshoot with the help of customer support (and even schedule a virtual meeting!) in a timely manner. The support is provided immediately and with the necessary knowledge to answer/solve any questions/problems I or my team experience.
dotcom-monitor LoadView is the only product like it that I have used. It's been extremely reliable and the organizations I have worked with who use it have been existing customers. I am sure other products like it exist, but I have never encountered any issues that would persuade me to start evaluating competitors
When using Azure Devops, it only has a basic test plan while using the extension, and it is better suited if you only use Azure Devops, but VS test professional provides comprehended test execution and management as most of the developers and testers use Visual Studio to develop their apps and publish their builds.
Visual Studio Test professional fits right in with the other Microsoft Lifecycle Management tools.
End to end, Development, Test, Deployment and Delivery assures the pipeline is continuous. Visual Studio Test Professional is an integral part of that pipeline.
Familiarity with Microsoft Tools makes usability intuitive, makes it easy to ramp up our Testers.