I've got 1/3 of an acre and I love mine. Ryobi 40V, 20", self-propelled. I used it all last year and can't imagine using anything else from now on. I didn't buy it brand new though; found a 1 year old model on Marketplace for half of what they cost brand new. I've got a few spare batteries as all of the other tools I have, hedge trimmer, weed eater, edger, are all 40V Ryobi as well