Changing from jet pump to submersible
This might not be any major insight but at least some food for thought.  

I think when the efficiency pays for the submersible quickly, it's a no-brainer - you want the submersible.  

The submersible is generally better made, benefits from running cool, tolerates debris, generally low maintenance.  

When you do have to service it, the submersible is a pain because you have to pull it out of the ground, but the jet pump is a pain because you have to prime it.  I'll call that a tie.

Like so many things it comes down to time and money.  The submersible is higher initial cost, the jet pump is higher ongoing cost.  In some cases where it doesn't run much and electricity is cheap, the submersible may never pay for itself over the life of the pump.  But it sounds like in your case you won't have to wait long for the payoff.  

In some industrial settings I see people not even think about the cost of the electricity - that comes out of someone else's budget and they want the cheapest possible up front cost, period.  Of course there are situations where someone can't afford the better pump today, so they have to take the cheaper option.  

But in your case it's a fast payoff so I think the choice is clear, get the submersible.