I started with Cuke4Nuke but have since defected to SpecFlow (sorry Richard ;-)
The main reasons for me to make that transition were:
- SpecFlow has nice VS2010 integration for syntax highlighting of features. There is a Cuke4VS project that offers similar but it doesn't haven't have VS2010 support (or not when I last looked anyway, which was fairly recent)
- I found debugging tests in SpecFlow to be easier (don't ask me to elaborate, it just seemed that way... ;-)
- Cuke4Nuke needed Ruby. I was OK with that but most of the C# devs I know get spooked by any non-MS products, Ruby in particular.
There are some issues with Specflow/things I like better in the Cucumber/Cuke4Nuke world:
- Specflow's documentation is quite 'lite' -- you will have to be prepared to work hard to gather info from Cucumber sources and intuit a bit how they apply to Specflow. That said myself and few others have designs on beefing up the documentation so that may improve over the next few months.
- I much prefer the experience of running Cucumber/Cuke4Nuke tests on the command line with their output of the scenarios color coded according to status (I know somebody above sees this as a negative so I guess it depends whether you're a command line kind of guy...)
- The Cucumber community is bigger and there's more activity it seems which (possibly) translates to more people out there to help you.
All in all both have potential to improve the way we write software.