Adobe Flex作为Web 2.0框架的优缺点

I came across the Adobe Flex framework one day. After watching https://www.adobe.com/products/flex/media/flexapp/'> the demo of Flex, it looks to me it is a bundle of different Ajax controls. I have no working knowledge of Flex at all and know very little about Flex. Therefore, I would like to hear from the developers here with some Flex experience to explain a bit more pros and cons of this Framework. In particular:I came across the Adobe Flex framework one day.