I did my first flex project a few months ago, too bad i can not show it because it is a pilot, but i can tell you that flex is a great product. But i think you don't understand how flex works, the flexserver GENERATES Flash movies! So everything which is possible in flash, is possible in flex.
Good thing about flex is that you can build amazing applications in a very short time period.
IE, i did build a search frontend with the Amazon Soap service within 15 minutes, and less as 20 lines of code.
Beware of the high license costs, about 20k for a dual cpu. Good thing is that you can download a developer versions that keeps working :)