I purchased my first robot 2 weeks ago. An Aquabot i2. It was only $385 w/ free shipping. It was completely worthless. About the only thing that it could do, was to pick up loose leaves and loose dirt floating along the bottom. It has no rotating brushes, just this pair of small orange stationary rubber brushes. I ran it 4 cycles and it still did absolutely nothing. Needles to say, I called the place I got it from (poolbots) and they had no problem with me returning it.
I then spent some time researching, and I believe the S200 will be a much better bot. I found a new open box one for $460 delivered. I should have it Saturday via FedEx. Very much looking forward to trying out what I hope will be a "real" bot cleaner!
p.s. I know the S200 is intended to use with an in ground pool but I don't see why it would not work with an above ground pool. Mine is an Intek 32x16 now on its 3rd season and still going strong. Best $1,200 I ever invested I think!