Grundfos SQF centrifugal vs. helical?

You don't give enough information about your needs. What is your confusion between the two pumps, their specs, the power consumption and your water needs? What's your well guy say?

My experience is well guys don't want to say much so they won't be on the hook... Kind of like when they show up and ask "OK, Where do you want it?" You say "Where would it be best?" Whey say anywhere. They might be better with pump selection especially for a more expensive one.

When I had my well dug I had them come back and sink an 11SQF-2 and cap it at the column. I built the rest of it from stuff available here at the store. I bought the monitor and the IO switch. You don't need any of that expensive stuff but the IO101 is cool to convert from DC to AC in a heartbeat just by connecting the power. No mistakes.. Frankly I don't use the Grundfos controller anymore. I'll make you a good deal on it. I run the pump off of a standard well pressure switch. No muss or fuss. There is also a precaution of people using the CU201 with the pressure signal and it didn't shut down, blowing lines. That pump can make a huge amount of pressure at 150' depth.