I just started using Demetra, specifically so I could check out the UI improvements, and I am impressed and pleased with the changes I've seen so far. The current version is a vast improvement over the first version. Much more intuitive, and I like the automatic handling of the layout as opposed to either removing and editing the layout manager or using the "insert/delete before/after" popup menu's. I also like how easy it is to move components around. The generated source also looks good, although I have only see what is produced when IntelliJ's layout manager is used. Good job.
I do have two small improvements to suggest. The first one is that there be a way to just generate the GUI source without having to compile the class. Perhaps an option off of the pull down menu where "Preview" is.
The second suggestion is to give us the option of changing the method names like $$$setupUI$$$() and $$$getRootComponent$$$() to something else. The reason for this request is because I have to deliver source to my customer and they always balk at the $$$'s in the name. I thought it was an excellent way to minimize the possibility of namespace collisions when generating the code and the $$$'s didn't bother me, but they have bothered some of my customers. I know it's easy to change, but if I could just set a different name in the UI configuration panel instead of having to remember to change it before delivering the final code, it would make life a lot easier for me.