I have researched the SImple Pump vs a submersible AC/DC Submersible pump. One advantage of using it in a PV direct mode is that it only takes ( if memory serves ) about 175 watts to run. The savings in Solar Panels would be pretty significant vs a grundfos submersible pump running on PV ( in my application it was somethere around 600+ Watts pf panels).
The flow rates are less, you you may need a water tank on the surface to store the water when the sun is shining, for periods when it is not.
I currently own a simple pump that is hand operated, but havent installed it in the well yet.