I have tried to be as objective as possible. Disclaimer: NUnit user since 2005-06.
- MSTest as an alias for the unit-testing fwk bunded with VS2010 v10.0.30319 throughout this post (although technically it is the just the runner). It's much easier to say than VisualStudio QualityTools UnitTestFramework. For NUnit, I'm using v2.5.9
- Class-Setup/Teardown - to be executed ONCE before/after ALL tests
- Test-Setup/Teardown - to be executed before/after EVERY test
Major DifferencesMigrating a test suite between the two runners might be non-trivial depending on your test code. MSTest and NUnit are very different in the way they go about running a set of tests. e.g. Consider a set of 2 classes containing tests - Class A with 2 tests, B with just one. If I insert logging at some critical points.. (I am looking at the default behavior - no customization)