There are only 3 advantages(that I can think of) to an electric pump:
1: Prime the fuel system without cranking the engine.
2: Longevity vs the chinesium aftermarket lift pumps. So far I have not heard many people complaining about actual Ford lift pumps failing, if they are out there they are quiet! I recently got a Ford unit for $30 on Ebay, they are still out there. Works great and stays between 4.5-5.5 psi all the time regardless of engine load or RPM.
3. If you're smart when installing, in the event of a failure the epump is WAY easier to replace in the field than the mechanical.
The disadvantages of an epump are:
1. Custom install vs OE but let's face it the OE lift pump is a PITA to get to with the fan shroud on.
Install includes a relay and wiring, usually some extra fuel line and good spring clamps. Making sure you use/make waterproof connections is imperative.
2. Costs a lot more to get an epump with the GPH and then add a regulator to make it consistent under all load conditions vs mechanical. And of course when it fails, it costs a lot more than the mech.