I like that it's easy to setup and get running in minutes or hours depending on your hardware. It has an admin console where you can see all status information about your cluster. There are few things which could be improved (e.g. the UI), but nothing really major. We needed something flexible enough for our needs - we wanted HA with automatic failover between clusters.
Sheepdog was one of the fastest solutions we found to this problem. With other products, setting up HA requires multiple steps