I too have a 280 and it does clean the pool well. All larger stuff ends up in the bag, including small toys and sometimes even goggles. Smaller particles and dirt are continuously blown around until they end up in the filter.
What I wish it would do better, which a robot would do, is sweep the sides of the pool I've noticed over the years that the walls are showing a bit of discoloration due to not being swept as much. I can scrub it off with a stainless bristle brush, but that is a pain.
Still given my choices, I'm fairly lazy and don't want to have to manage a robot. The 280 stays in the pool all the time, runs on the timer and just keeps it clean.