I didn’t see this article before today. That’s really impressive results, but as they point out GUI development is the hardest part in Java. We spend way too much time tweaking GUI stuff compared to business/application logic.
Another weakness is the learning curve of the J2EE frameworks. The 4GL has a much lower learning curve sacrificing control. But like one of the older experienced 4GL guys at work pointed out; you don’t have control when something goes wrong, but then it’s just as easy to work your way around the problem with some drag and drop.