05-02-2011 01:12 PM - edited 05-02-2011 01:13 PM
I just wanted to throw my two cents in on this... sorry for coming late to the party
I started out learning pure as3 years ago and have moved to using flex at times. That being said if you are looking to learn anything, you should learn as3 first and then move towards flex ( IMHO ). It is important to spend the time to learn when to use flex.
About 90% of the time when I do use flex, mind you, I am doing so in as3 code, not MXML. I find it much better to write the code myself rather than drag and drop. If it can be done in MXML, it can be done with as3 ( with or without flex ).
I prefer to write everything from scratch when I have the time to do it, however, there are times when I really need to push something out and the overhead/ease of flex is acceptable. To me, however, the smaller the filesize the better, though I still have the mindset that we had to have when dial-up was the prominent connection type.
My first PlayBook application was written in pure as3 while my second was done with flex. So far, I like how smoothly the as3 app runs over the one done in flex. I might take the time to rewrite the second app so I can compare and contrast the performance and then make the decision on how I want to move forward with my mobile application development.
A quick aside: If I were writing a game the last thing I would use would be flex if I were concerned about performance.