For just a few forms I recommend using a Builder. It will get the done way faster. However, if you have a lot of forms that you need to maintain for some time, I recommend against a builder. For this case the time you spend in reading the code and maintenance is much larger than the initial design time. So, while the builder saves you some time at the initial phase, it makes code reading and maintenance more difficult. More over, it makes code re-use, even in the form of copy and paste from one form to another, more difficult.
I don't know if you are referring to web or desktop applications, but in general I haven't found a Java Gui builder that produces elegant output. Netbeans Swing generated code for example is a mess. Perhaps, if a nice builder were available I would change my mind. I had no problem using Visual Studio's form designer - it produces nice code that you can read and understand.
For desktop applications have a look at MiGLayout. It's a layout manager, not a builder, for Swing and SWT that will make your life easier.
