I have a Dolphin Explorer E30 and am satisfied with its performance. I do not see a reason to pay more! On sale, it was twice as cheap as Sigma and Supreme. It cleans waterlines, floors, and walls. It has only one cleaning cycle, but it is equipped with an extra-large filter basket. I control it with my smartphone. If you find dust and want a gyroscope, then it makes sense to choose between these models.

I have had Dolphin Nautilus CC Supreme for half a year. It is my first robot cleaner; before that, I had a suction-side automatic model. I do not understand why I have waited so long to purchase it; I forgot about the dirty pool!

I consider Dolphin Sigma a theft! It did not last the warranty! I had to repair and replace the motor. I did not pay for the repair, but I had to clean the pool manually for two weeks. I would prefer not to experience that.