I worked with ocfs2 for a relatively short period of time on two RHEL4 hosts which shared a filesystem (housed on an EMC SAN). It was a snap to set up, and it worked as advertised. In our case, the ocfs2 filesystem was used to accommodate Oracle RAC.
I don't really have any "battle stories" to share.

The project received hardware funding, entered a political tiff among whiteshirts, and was abruptly canceled.