Got my first one a little over a year ago. The motor that turns the blade burned out. The self-propelled moter was fine. But no blade, no mowing. Ego return pretty much made it impossible to fix unless I paid all shipping, to and from.Well, I already had 2 batteries, so I figured I'd just get another, this one being doule-bladed. So far, it mows about the same. It consistently leaves blades of grass (St. augustine) uncut on the edges. So, it's not really 21" cut, more like 18 because you have to take less than a full width pass to get them all.And, both of them have the same problem with the self-propell, so I know it's not just a fluke. Any time I'm just pushing it, without using the self-propell, if I try to turn sharply, the self-propel motor engages but doesn't turn on, so it creates a huge resistance, kind of like putting a 4wd truck into 4 low and trying to take a sharp turn on pavement, if you know what I mean. It binds up. And it does this all the time. Very frustrating. I wanted to be good to the environment, but if I had to do it over, I'd just go back to good ole Briggs and Sratton gas mower.