I have to replace my Hayward Pool Vac after 15 years of use. It is the standard white one that cost 300 bucks 15 years ago. It is attached to the basket at the skimmer and runs on vacuum. I'm putting in a new VS Pentair pump and a new spa heater Raypak ng dig heater (400 power) this winter also. I'm hesitant to experiment on new cleaners so an leaning on just replacing the Hayward with the ultra or possible go with the one with the 2 wheels. Our pool is not large and is about 25K gal. the deepest part is 5 ft deep and all corners are rounded, except for some steps that are no so round. So stick with what I know or what? I read that the 2 wheel version mates up well with a VS pump. My only complaint about the original Hayward is that the round seeds from a palm tree get caught up in the suction area and just bounce around enuf to make the unit stop moving. The seeds are about fair size blueberry size but hard. Would the 2 wheel version work better? also what's with the 2 different Hayward cleaners with the two wheels? One is cheaper and has a different farfignuton type name attached. Is it basically the same but different? I thought about robots, but I'm retired and home enuf so I can do some manual work without any problem.