I've never learned to use Emacs. I love vim, but it doesn't scale for me when editing more than three files at the same time or projects with more than one directory. After two years using Eclipse for Python and Windows C++ development, I've been using almost exclusively Eclipse for X.Org/Mesa/DRI development during the last three months.
I think Eclipse is really a pleasant development environment:
- it has a good code navigator, which is also fast (they used Mozilla's source tree as a benchmark);
- excellent support for remote debugging (embedded companies are major contributors to Eclipse, since almost every embedded SDK nowadays is based on it);
- it rarely stands it the way (e.g., it integrates with any build system from autotools to hand written shell scripts, you still have the power of regular expression at your finger tips, etc.).
Also, the CDT (the C/C++ Development Plugin for Eclipse) folks are now actively working to get Eclipse not only to debug remote applications, but also build remotely, which will greatly simplify testing on multiple software/hardware configurations.
The thing I miss the most is better git integration. Of course, it is advisable to have a big screen and lots of memory.
For those interested, I've wrote some instructions to get you started on the X.Org Wiki.