What the (Java developer's) world need is a tool that automatically
converts apps from Swing to SWT, and vice versa. Probably not a
trivial pursuit, but it would have both toolkits compete on a level
ground. The following is very wise, taken from SWT wiki:

 "Which one is better: a screwdriver or a hammer...?"

I am a highly visual person, and frankly, SWT looks beautiful:

  http://www.eclipse.org/swt/

SWT does not try to place a tinted, distorted glass over the Mona
Lisa, as Swing does.

The whole issue (I am talking strictly about the visual aesthetics)
reminds me of the comments when the Macintosh came out:

 "How come the Mac programs seem to be designed by an arts major
while Win3.1 look designed by an engineering major?"

and, my all-time favorite:

 "The Macintosh is to Windows (3.1) as a beautiful woman to a
transvestite".

In speed of response terms, the one and only widget in which you can
see a substantial difference is in the implementation of JFileChooser.
Swing's is dismal, awful while SWT is perfect, like the real thing
(see transvestite comment above) because it IS the real thing.

I tend to disregard the "productivity" arguments, as the learning
curve is minimal compared with years of daily use. Once you learn one
of the tools well (however long it takes) you will be productive using
it.

Having said that, I have never used SWT, I use Swing because of
inertia. I learned Java with Swing-only JBuilder and following the
Swing only Java Tutorial. I didn't even know that there was an
alternative to Swing at the time.

Some people say that one fundamental reason for Eclipse's immense
success is its use of SWT.

-Ramon

ps:

SWT home page - Standard Widget Tookit - SWT download - http://www.eclise.org/swt
Where is SWT? Where can I find SWT?

Flame bait, but meant as humo(u)r, not a serious condemnation of Eclipse.

Sorry, but Editor Wars
<http://en.wikipedia.org/wiki/Editor_wars>
have been around too long for me to take them seriously.

I've been a vocal critic of many of NetBeans's flaws in the past, but in the
end I use the tools that are available.  Hey, I even use vi if emacs isn't around!

I only use NetBeans because emacs doesn't have a good Java debugger.

In all seriousness I really do find NetBeans significantly more
straightforward to deploy and use.  Eclipse and its (grand)children have
always struck me as kludgy, top-heavy and obscure.  NetBeans comes across to
me as clean, direct and minimally intrusive.