The only disadvantage I see to that is the fact if they want to get into a turbine, they can spend the same amount of money and get a small turbine with basically better or similar performance and faster turnaround time on the ground (which would give them more flights per day). Looking at the cost of the batteries and assuming one would need two sets in order to get the same amount of flights per day that you would get out of a turbine, it might even be more expensive. Don't get me wrong, I love the fact that we are seeing this happen. It may open the door to those who do not want to do the waiver process (again not that this is a bad thing, but options are good). It also may revitalize some of the smaller jets where turbine technology is an overkill. The JHH A7 is a great example. Their plane is a great look airframe (no spindly looking retracts) and appears to operate really well on the EDF package.
The future looks bright for this technology.
Tommy