We've not had any issues arise as of yet (touch wood) with the fail-over cluster splitbraining at all. To be fair, the cluster has been pretty stable. Although that's not to say that we haven't had issues, but the issues we've had have been more down to the OS as opposed to the cluster itself.
We are also running SQL Server 2014 in a fail-over cluster environment as well, so are running a cluster within a cluster to add an extra complexity to things lol.
We currently have two main fail-over clusters running at the moment;
6 node (IBM x3550) cluster hosting approximately 30-40 virtual servers at present.
5 node (IBM x3650) cluster hosting approximately 70-80 virtual servers at present.
Thanks for that. I've just setup a cluster for an Exchange 2013 DAG, which was interesting.