It has the potential to mimic Sacred Shield's effective hps/absorb on the tank if you can maintain a 3HP EF on the tank and a 3 HP EF on one raid member at all times, you need to be generating 6HP every 30 seconds for this, not counting Divine Purpose. If you also count the second EF as useful raid healing, and SS as effective hps, EF seems to win. (Starting pulls with 5HP really helps this style)
What you lose doing that though is the LoDs you could be casting while Sacred Shield sits on the tank w/o costing any of your precious HP. Here you can treat Sacred Shield as granting you 6 free HP exclusively for tank healing/mitigation each 30sec.
Personally I prefer EF whilst I'm still using 4p PVP as it has the added benefits of refreshing my mastery during the hot, potential of many more than 2 EF rolling into tank, ability to send all EF ticks to anyone by swapping beacon to them(Tsulong), and I enjoy the more spot heal/pre-absorb method of dealing with aoe damage.
I've added some of the math I used to come to these conclusions.
6 ticks from SS = 164,030 @23,073 SP, 11 ticks+initial heal from EF @23,073 SP/31% mastery = 112,735.
164030 - ((112,735 * 1.31) + (112,735 *0.5)) = --40,020
i.e. 2 EF style wins very slightly (25% more healing) if all ticks are used.
Holy Shocks for 2EF
No Set |PVE 4P |PVP 4P
6 HS = 36s |6 HS = 24s|4 HS = 24s
Hopefully I didn't ramble on too much and this helps you make a decision on which talent to use.