I've blogged about method and var handles recently: http://in.relation.to/2017/04/11/accessing-private-state-of-java-9-modules/.

One thing to keep in mind is that deep reflection will be allowed by default again in Java 9 as per the recent addition of the "big kill switch". Still we should be prepared for this not being the default any longer. As we require Java 8 now anyways, I think we can already do the switch to method handles right now.