I am using FDT for about 3 years now. I have used it almost exclusively for my current project. The support team is very helpful and will respond to your questions promptly. If you are looking for an IDE that provides many features out of the box, this is not for you. There is too much customization required if you want anything non-trivial like creating custom actions for instance. However once you get used to the way things work, everything becomes easy. I have been able to create complex UI without any issues. I can easily develop rich client applications from scratch or modify existing ones. I cannot think of anything that I dislike at the moment. So far I haven't found anything that I disliked. The only issue I face is occasional slow loading speed when working with large projects. But this isn't really that significant a problem. Support is also very good. In fact, we are using it.