One small thing that makes Consul exciting (especially when compared to etcd) is its -bootstrap-expect flag [0].
It's the recommended way to stand up a Consul cluster without a risk of causing split brain if it turns out multiple nodes are coming up at the exact same time, and it achieves that without an external / pre-existing coordination service.
In comparison, etcd's recommended way to bootstrap a cluster is to use CoreOS' "discovery" service, which is great, but does constitute one extra dependency.
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Now, the downside of Consul is that it seems etcd has much more momentum.
[0]: http://www.consul.io/docs/guides/bootstrapping.html