Preliminary data suggests that an MVP or sub-MVP in Expert gives better ticket return per BP than no MVP in Ragnarok, and better average medallion return regardless of MVP status.
Sandalphon event drops (browse to tab)
In addition, Ragnarok is only slightly better even if you can guarantee MVP (which you generally can't unless you started it). Seems like Ragnarok is only best for weaker players that can't MVP or sub-MVP the Expert quests. Also, the ticket return is pretty awful if you can't at least sub-MVP any of these.