Explanation sought

[FossilPhill]

In the process of looking for a replacement pump with similar characteristics to the existing pump, I have come across two different brand pumps with similar flow, head, and performance, however, the one claiming the slightly higher performance is a 550 watt motor, and the slightly lesser performing pump is 750 watt motor.
I cannot understand this, as I would think that more power means more water.

The two pumps are as follows:
Lowara (Goulds) XBGR100 750 watts
Hyjet Maxijet HSJ550 550 watts

Lowara 32M of head @ 20 l/m Hyjet 36M of head @ 20 l/m
Lowara 19.9M of head @ 60 l/m Hyjet 21M of head @ 60 l/m

 

[Valveman]

Some pumps have a higher service factor than others. Read the pump specs or look at the curve as that is what matters. They sell a ton of those pumps with that flow switch controller on them because they are made to sell and not to last. Get a regular shallow well jet pump with a normal pressure switch/pressure tank and you will be much better off. Adding a Cycle Stop Valve like comes in the PK1A kit would then give strong constant pressure to the house while making the pump last several times longer than normal. That "making the pump last several times longer than normal" is exactly why you see those flow switch control things on pumps that come from the factory and will never see them promote a Cycle Stop Valve.

Sounds like you may not even be in the US. Getting a Cycle Stop Valve shipped to any other country is difficult but we do it all the time.