I guess I should have said 'one of the best IDEs I have tried' :)
I should have been a bit more rigorous in my statement...

Now I come to think about it I realize I am not the most indicated to do an informed comparison of C IDEs, I have not used that many. Yet I'll give my opinion in case it helps.

For me, the most important features of CB are that it is free, it is cross-platform, comes with an integrated toolchain and is very easy to install (point-and-click, usually) and very comfortable to use. For casual use or for a student, this alone makes CB very convenient.

As compared to Eclipse, CB's major advantage is better integration with 'gcc' and 'make', in my opinion (I know others will disagree). That, and it is far smaller and faster than Eclipse, which may be very important in older machines. Eclipse CDT is widely used in embedded development and has a lot of supporters, it is another possibility worth exploring.

Apart from that, CB has all the usual features common to all modern C IDEs: code navigation, syntax highlighting, automatic code formatting, integration with a debugger (gdb, included), etc.
It is mostly on par with other free and non-free IDEs (Eclipse, Keil uV 3, TI Code Composer for example). Plus it is very fast and very configurable.

So, while I should not have said that CB is 'one of the best', it is certainly worth a try :)

More advanced users (Per?) will be able to offer much more insight on this IDE and others.