Netbeans comes with a great gui builder, and seems organized around drag and drop and "properties editing" type development. Eclipse is definitely focused around Java correctness and making sure what you're typing is correct. Eclipse feels like it's compiling faster, I think it's doing incremental compiles so productivity feels high and is.
If you're not afraid of IDEs that look scary at first, learn Eclipse. I often feel like I don't know Java at all, like I've outsourced my job to it ;)
Refactoring (right click, refactor in the Package view), Autocompletion (Alt-forward slash autocompletes), Search resource (Control shift-r) and constant error highlighting with suggestions make Java coding as easy as recording your thoughts on an mp3 player.
In fact, because it's so powerful, I often write out quick Java sketches, and as I make massive design changes later on, all I have to do is drag and drop with the refactoring option to restructure my app as I want it. Definitely a wonderful thing.