swstant -There is an old Texas saying that if you put lipstick on a pig, it may look prettier, but it's still a pig. Flex is lipstick. Macola, on the hand.....
Flex is right for you if you have someone available who has a working knowledge of both Macola and Visual Basic. In addition to the limitations chadt pointed out, I find Flex's biggest limitation is the really, really poor implementation of the event model. VB code is designed to react to some type of event that occurs, such as your user pushing some type button, or saving the file or initiating a Macola program. Unfortunately, Macola seems to skip the implementation of certain event entry points, so sometimes your screwed when you want your program to do certain things, and it always seems to be that one thing you really, really need. If the event model allows what you want to do to be done, it will be worth it to pursue the expense of a Flex app. Otherwise you can get into some real ratholes. So step carefully.