With 2.5 comes Rack Awareness, which suggests replica data will automatically be kept on separate AWS availability zones without the need for XDCR or additional configuration.
How does Rack Awareness replication compare to XDCR?
Is XDCR different in any way, is it better on bandwidth, does it compare changes differently, is the protocol different?
Which is AWS best practice? Rightscale with modified recipes to use server groups based on availability zones?