Other than IPv6 support, is there a reason to use Calico/Weave over Flannel? We've been very happy with Flannel, especially using the clean CoreOS-Flannel integration.
In the case of Weave: encryption, multicast, fault tolerance (fully distributed through a CRDT mesh), integrates beautifully with containers (can be used as a Docker network plugin and provides out-of-the-box service discovery). More over, it's stupidly simple to use and setup (zero-conf, no kv-store required).
