MCX Settings from an AD Domain Member?

Hi guys, 1st up thanks for all the info in the past it has been really helpful, but I need your collective experience again!! So, I've started @ a new place & here config is as follows: DC for authenticaion & Exchange 2k3 OS X X-Serve that's a domain member & file server 10.4.6 Bes Server 2k3 SQL Server 2k3 The client base is 65 Macs & 5 Pc's.... ;) Also, I manage them all....:D So, what I wanna achieve is MCX settings (incl. PHD's) for the Mac Clients... PHD's for hotdesking isn't needed, just DR.. So one MCX group (or computer group) should be fine, trouble is with the X-Serve being a domain member I'm guessing that it cannot apply MCX settings? So, If i wanted to apply MCX settings what option would you guys choose: Extend the AD Schema? or Set the X-Serve as an OD master.... (magic triangle)... Also, what are the pitfalls of extending the schema (once done sucessfully)... Cheers in advance!