Mark writes:

could someone please tell what you think of these?

Takes power to clean stuff. Why do you want a cleaner that doesn't use
much power?

The Polaris units with booster pumps are the thing to have. 180, 280, or
380 models. It doesn't just pick up debris, it circulates the water and
chemistry that would otherwise stratify and stagnate around the bottom. It
might cost 10 or 20 cents an hour to run a 3/4 HP pump, but it gets the
everyday job done in an hour or two.

I have cleaned up after several hurricanes using the 180, where the bottom
was literally covered with debris. Other than hauling out the Polaris to
empty its bag, I never touched a vacuum unit or scrub brush.