There are a few things to consider in the debate of Eternal Flame and Sacred Shield.
First of all is the number of ticks in relation to haste. Currently at level 85 you gain a 13th tick at 24.97% haste, which most of us will be at with the 5% Spell Haste buff.
Is this for EF or SS? SS does scale with haste, being that more haste reduced the time intervals between absorbs (i.e., from a shield every 6 sec to a shield every 5.2 sec).
Additionally, EF ticks gain from Crit (not sure if the ticks grant Mastery or not), where SS does not.