What are the differences between using a VS integrated tool like Testdriven.net or using a GUI test runner like Icarus or NUnit GUI?
What do you prefer and why?
So far i've found that reports are better in Icarus than in td.net, which only features a commandline output. However td.net is faster to use, i can execute single tests more easily without having to uncheck the rest first. NCover integration is very nice also.
Icarus has one great feature that keeps me using it. It is the automatic reload and rerun of tests.
I keep Icarus hovering over on the left hand monitor. Each time I build in Visual Studio, Icarus reloads the assemblies and runs all the tests. It's sort of like the instant feedback of Resharper's Solution Analysis, except for tests instead of syntax. Running the tests is automatic and doesn't seem to affect the performance of Visual Studio (likely b/c Icarus is it's own process, not hosted inside the IDE).
To enable this configuration go to Icarus->Options->Test Explorer. Check 'Always reload files' and 'Run tests after reload'.