One of the best new features in ON1 Photo RAW is the new local adjustment brushes. The local adjustment brush works just like the masking brush and has the same Perfect Brush option to turn on to detect edges. It also allows you to selectively apply your adjustments and the ability to adjust the settings after the brushing is done.
The masks are really powerful on adjustment layers. You can copy and paste them, invert them and even create luminosity masks. You can also stack multiple adjustment layers. These can make a huge difference in your editing by just using a couple of the local adjustment layers.