OD provisioning accounts from LDAP

The lack of Win7 support in Apple's implementation of samba is causing quite a headache. We've looked at getting a Samba 3.4 PDC working with OD, but are finding we have to make too many changes to Apple's ldap schema. This seems a dangerous course to take when taking upgrades in mind. Going with AD is not a solution we want to implement. Has anyone bound OD and provisioned accounts from an openldap server? If so, any pitfalls? Regards!