I used both. We have moved from Cruise Control / Nant to TFS.
The big advantage and the reason we moved is the integration and reporting capabilities.
Nant is easier to work with simple projects. But if you have a large environment, and you look at it as a software development process, and not just a build server, then I find TFS much better.
Just use what makes you the most productive.
Shiraz bhaiji
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