At my work we use CCNET, but with builds on check-in more than nightly - although it's easily configured for either or both.
You can very easily set up unit testing to run on every checkin as well, FXCop testing, and a slew of other products.
I would also advise checking out Team City as an option, because it has a free version, and the reporting and setup is reportedly much simpler (it does look nice to me). It does have a limit of somewhere around 20 team members/projects, before it hits a pay-for window.
That said, we started with CCNET, and have grown several products too large to look at Team City on the free version and are very happy with what we have.
Features that help with CCNET include:
- XML based configuration - you can usually copy and paste most of what you need.
- More or less you'll be able to plug your treesurgeon script in as your build script, and point CCNET at that as an executable task to run the compilation.
- Lots of documentation and very easy to set up nunit, ncover, fxcop, etc.
- Taskbar app that will let you know the status of your projects at any time, and it can also fire off an email or keep an RSS feed with the same information.
But I'd definitely go with running a CI build on every check-in - for the most part will run the unit tests before checking in, but let the CCNET server handle run any applications/assemblies that would have dependencies on the assembly we're checking in, and they get re-built, and re-tested on every checkin.
Given that CCNET is free free and takes very little time to set up - I'd highly recommend just going for it and seeing if it suits you, then expanding from there.
(There's another thread here where I posted pretty much the same/with a few alterations - but some of the other comments may help too! Automated Builds)
Edit to add: You can easily set up your own deployment scheme for CCNET, and there are a tonne of blog posts out there to assist, and email notifications can really be set up fairly granularly, either on all successes, all failures, when it changes from success to fail, etc. There's also built in RSS, and you could even set up your own notifiers for other systems.