I'm confused by your question as it relates to the ZFS storage appliance. The appliance runs a version of Solaris 11, not Solaris 10,
but maybe you are providing devices from an appliance to a server that is running Solaris 10 1/13. Can you clarify?
I don't have a Solaris 10 1/13 doc pointer that describes you can keep pool capacity at 90% for best performance, but this bug identifies
this doc issue:
Bug 16978258 ZFSADMIN and SOLTUNEPARAMREF do not reflect 90% for pool capacity recommendation