Where is it written that the -Z approach is default? Don't take offence please, it's a genuine question!
Although from a practical point of view the two approaches are identical, so I wouldn't get excited either way. The distance from the SY VOR and the touchdown zone seems to explain the DME difference.
Let's remember that you don't actually need a DME at all to fly an ILS, once the integrity check is completed. From a practical point of view, that is.
Last edited by Oktas8; 9th Jun 2012 at 09:19.