I really want to get to know Flex and Actionscript 3 for developing hobby/educational purposed flash games to get my feet wet. I jumped in at kind of a bad time I suppose since FB4 just came out and there is little help for creating a game as you would in Flash CS4 + AC2.
I have yet to see a decent game that was developed in FB4/AC3/Flex (the best was Tom-As3-gotchi), yet I see quite a few advanced games made with basic Flash + AC2. I am in an intermediate Java/OOP course atm and alot of the nature of Flex really appeals to how I have already been programming but it seems like in order to make a hamburger in Flex you have to kill the whole cow.
I do understand that the habitual nature that games are created in Flash are very bad programming practice, and frames to me are just really ugly. The biggest reason Flash appealed to me for starting out with AC2 was I could create an object and immediately apply code to govern it graphically and codedly.
I hate the concept of using AC2 because lets face it, I want to stay with the most up to date version of that scripting language and I would expect one to be able to do everything the previous version did, but thats not the case.
flex is not good for games because of performance compared to pure as3