Saints were deserved winners last night.
As others have said, it's virtually impossible to compare across different eras. For me, what's most impressive is the consistency from Saints across the SL era. This is a different issue from proclaiming them the 'best team ever'. For that accolade the best objective yardstick is being able to win all the domestic trophies followed by the WCC, but even then it's legitimate to consider the quality of opposition in a given season, so not easy.
My personal 'greatest SL team ever' is the Bulls of 2003. In those days the likes of Peacock and Vainikolo were simply on a different level... But I accept this is entirely subjective. Saints with Jamie Lyon were also pretty special.