I don't have a lot of experience with SNS, but I'll be happy to look into it.
RE: the differences between 1.9 and 2.x -- version 2 was a complete rewrite, including a change of frameworks, causing many of the differences you see. We also took the opportunity to implement some best practices, such as adding the api versioning to the api path (you'll notice most public APIs do this.) We did our best to document the significant changes: http://wiki.dreamfactory.com/DreamFactory/Tutorials/Upgrading_Your_App
The wiki also has release notes for each revision.
Anyway, like I said, I'll check out SNS and see what I can find.