I'm looking for a budget (~$700) robotic pool cleaner. As you might imagine, the market is a bit over saturated and confusing. On my list are all $600 options which include the Aquabot T-Jet, Dolphin Nautilus and the Aquabot Junior. As of now, I'm leaning towards the Dolphin Nautilus but I would love to here recommendations.

I have a 19x37 inground pool with a vinyl liner (I live in upstate NY). For filtration, I have a sand filter.