Eeeh... WHM have nearly no issues with MP end game, so MP efficiency is kind of a moot point in easy content. So if you ignore lower MP cost and a possible free Cure II all you are left with is a weaker heal.
While that is (partially) true -- and I say 'partially' due to still noticing CureII-only WHM's asking my BRD for refreshes -- what happens when this factor changes and everyone is stuck in a Cure II mindset? I didn't post my comment as a means of glorifying MP saving, I posted it because Cure II is still gross overkill when Cure (with or without buffers) can cover 65% of scenarios AND trigger free-cure for your Cure II's anyway. If SE randomly decide to tweak the MP consumption for WHM's, yall gonna suffer more than I will due to finding no real need for Cure II other than emergency situations (which is technically how it should be used anyway).