Seems the Eurocontrol valid route SOPOK Y863 ROPUV L607 ABUKA KRH NATOR LUTIX BENOT
is placed above the VATSIM cleared route ROUSY GTQ POGOL LASAT MOROK Z24 AKITO
and thus offered by default.
But the VATSIM route (which also passes CFMU validation) has 9% overhead + SID/STAR whereas the default route has 47% overhead + SID/STAR. The VATSIM route seems more prevalent on edi-gla as well.
Regards,
Tim