Absolutely worth it. I'm already getting started adding the new CB 1.2 to a site I'm developing. I'm not worried about the RC status because these guys are very talented programmers and I don't foresee any major issues upgrading.
The documentation is very useful and will save time getting up to speed on the new functionality. Not only that, when people subscribe it gives the development team more time to spend working on Community Builder rather than doing other stuff to put food on the table.