God bless you for native Windows theme in CIS 5.8. But, can you add native Aero theme? Take Outpost for example: they are still using their own graphics (“identity”), yet they managed to combine theme with Aero elements perfectly. It looks so darn sexy! If you will do the same, I swear I’ll come to USA and will be kissing your foots every morning until release of CIS 2013!!!
P.S.: There will no performance hits as all those elements are in system already.