I've been a Vim user for a couple of years, and love it. After a steep learning curve, your coding speed increases dramatically. As good as IDEs like Netbeans and Eclipse can be, the normal operations - navigating round the file, editing, copying, pasting, deleting - are never as efficient as they are when using Vim.
If you're a regular user of Netbeans IDE then, like me, you might sometimes get the feeling that you're not using it to its full potential. Take debugging for instance: did you know that you can use Netbeans to debug a web application by pausing at particular lines of code, and get a list of all the variables in the current scope? It takes a bit of setting up, but you can do it - here's how.