We are looking into moving onto 6.7, but it will be some time before I can get to us sit in earnest.
I am hoping to get it onto the 'sandpit' rig first, so I can see what improvements there are in several areas, and the interaction with the Dell Compellent SANs is one of those.
I have spent some rather interesting time over the last couple of weeks getting down into the weeds of the SCOS CLI, resolving some issues. There is some good stuff on the CLI but it's a bit of a jungle in there and not for the feint of heart. The 'sandpit' had to be cleared of important stuff when I started getting nervous.