Yes, we are using Flex in our application. It is pretty easy and quick to develop in Flex and their builder is worth all the money. Action script is very simila

Yes, we are using Flex in our application. It is pretty easy and quick to develop in Flex and their builder is worth all the money. Action script is very similar to java script so it is easy to pick up. I huge pro is that you don't need to worry about browse compatibility. Also a few extra good things are that the sdk is going to be open source and that mainstream websites already make use of it (for example yahoo maps and messenger are in flex). I recommend to at least try it before you turn your back on it.