At $559 the Poolmate Hydro 3S was also a surprisingly good cleaner, with a 150-micron fine filter basket that opens at both ends for cleaning and extremely good suction, and the only reason it didn’t take the top spot from the Aiper S1 was that it struggled a bit with the sloped floor of my pool which caused it to have lower than average wall coverage, but for a flat bottom pool, I think the Hydro 3S would be hard to beat.
