Is NUnit better than MsTest?
The most common unit testing frameworks in the.NET ecosystem are MsTest and NUnit. Microsoft’s Visual Studio includes MsTest, a native unit testing library. NUnit is an additional Nuget package that must be installed on top of Visual Studio in order to communicate with its APIs. Nunit, unlike MsTest, is unlikely to have direct interface with native APIs.
As a result, MsTest is faster in my experience.
To get more detailed difference between two read here