I realize you're referring to Swing Java apps, and I won't argue on their behalf for a second. However the SWT library is a dream of a native toolkit experience

I realize you're referring to Swing Java apps, and I won't argue on their behalf for a second. However the SWT library is a dream of a native toolkit experience if you're writing a client app in Java. It's fast, does a good job of working across a wide variety of platforms (Win32, Cocoa, GTK, and I think Motif), and is extremely well documented.