Robots for AGP - Thoughts, questions and considerations

In my research for robots for my AGP, I have become irritated. Search any pool store site for robots for above ground pools. You get to choose from robots that clean the floor and the cove if you are lucky. They have (mostly) stationary scrubbers and seem to function about as well as a glorified suction vacuum. Reviews are bad or at least contradictory.

If you have an in ground pool, you can choose vacuums that clean the floors and walls. They have scrubbers. There are really great reviews by hundreds and in some cases thousands of people that have purchased and used them.

So, why is this? Are the walls of an AGP covered​ in a vinyl liner really so different from an in ground vinyl pool? Is it because the walls are curved instead of flat? Can the vacuum not figure out how to move in a horizontal pattern to maintain even contact with the wall? I have also noticed that sometimes in this forum in ground pool vacuums are recommended for above ground pools. How will I know which ones are ok?

Right now, the Doheny Saturn (considered an in ground pool cleaner) is at the top of my price range and is my main contender. Others on this forum have mentioned that fewer brushes (2 or less) would be less harsh for a vinyl pool. This has one scrubber and is supposed to scrub floors and walls. The next contenders are about 1/2 the price, Aquabots mainly. I don't want to buy a pool vacuum that stretches the budget and then doesn't perform as expected. So many choices.