The Dolphin Pool Cleaners have distinct design advantages.For one, The cable plugs into a watertight socket. Second, direct drive eliminates the need for drive belts.
Unfortunately, it is the direct drive that is also the robots undoing when a very small item gets jammed in the drive gear and burns out the circuit board.
If Maytronics offered major repair parts this would be less an issue.
Buying Aquabot is much much more than buying American. It's buying a machine that can be repaired for less than the cost to replace it.
Other Machines to Seriously Consider,
At the upper end is Blue Diamond. The same machine as Aquabot Bravo. Great reliability, four year non-prorated warranty on the motors. Many people think it is too fast as it races over dirt.