I'm using NetBeans for J2ME development and have created a visual midlet for a reasonably simple flow. Whilst it's all very pretty, it reminds me of the last time I used it as the VMD files seem to corrupt quite easily and are difficult to fix. I've also noticed it can leave lots of junk when elements are removed from the diagram. In the end I got the flow to a reasonable state then stripped out all of the visual code.
NetBeans is great for the rest of J2ME development, especially the packaging.
Do other people have much more luck than me?