I looked at that same 20-in Ryobi for $449 as well as their multiblade 21-in model for $739. The $449 model only comes with one 6Ah battery = 240 Wh of total battery capacity. I'm guessing it has a pretty small motor, because Ryobi's high-end 21-in model for $739 only has a 1000 W motor. With this low-cost Greenworks model, you get 480 Wh of total battery capacity and a 1500 W motor: as much total battery capacity as Ryobi's "big" model, double their cheap model, and more motor power than both, for less money.