Its a strange process building using a heavy component based environment verse pure AS3 development, where you design the structure and GUI from scratch. Flex3 is great for quick UI building, gives you a chance to test usability with the client before full scale implementation. The development process I find is more Test Oriented Development where you can try UI designs quickly, pull back and try a different approach or take the first path further.

This kind of development where you get feedback pretty quickly from a user and yourself, I find opens more doors than time can sometime allow. Leading to more backwards and forward stepping than I usually take when developing from a set visual idea and building the structure in AS3 to produce the result.

I also find myself feeling slightly disconnected from the structural process in Flex3, sure things seem to work easily and produce visual results but its not having that pure understand of the structure through scripting the entire application yourself!

I am too obsessive by wanting absolute control? Must admit I did grow up playing with Lego.