Workflow for swf decompile and edit

I have had good success using the Application Builder ("ArcGIS Viewer for Flex") but am ready to go a bit deeper and use the flex api. However, rather than code everything up from scratch, I'd like to be able to use my existing viewers as a starting point for further development. Specifically, I'd like to be able to crack open the compiled .swf that comes out of the AppBuilder and use Flash Builder to edit the ActionScript and .mxml components.

A bit of digging online revealed this product, SoThink's SWF Decompiler.
http://www.sothink.com/product/flash...r/download.htm

I'm curious if anyone else has tried such a workflow, with this product or a different decompiler, and if it was successful.

Thanks,
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