There are 2 interesting new features on RAC 18.104.22.168.
The first is the cluster HAIP resource, that makes possible to have up to 4 redundant interconnects that will be automatically managed by the cluster for fail-over and load balancing.
The second one is the Cluster Health Monitor. It was previously available as a utility that you can download and install, now is a resource on the cluster and will start to collect valuable OS statistics from the moment the Cluster is installed.
You can see details about both features on this file : HAIP and CHM 22.214.171.124 RAC Features