I have been wanting to work with NetBeans RCP for quite some time now, but I felt that resources were lacking; then came along API changes for NetBeans 6.0 Platform and I felt there is a lot of improvement in it, along with its platform home, the excellent RCP book and Maven integration for plugin/suite/Rich Client Application development (I personally tested it whether it works or not and it does smoothly except that when I was reading it Figure 4 and Figure 6 were in opposite places), now I reckon NetBeans RCP as a force. The biggest advantage of NetBeans RCP that actually initially dragged me to NetBeans was the JavaHelp integration.
I just wish NetBeans also support(s)/ed GIT. Actually I am planning to add support for it in NetBeans.