Because I mow on hills, I'm in need of a 2 cycle self-propelled lawn mower. I considering either the Snapper Hi Vac with rear bag, 4HR Robin, 2 cycle, with 6 speed disc drive at a cost of $799 or Lawnboy's Silver variable speed self propelled, with 6.5 Duraforce 2 cycle, rear bag at a costs of $378 or the Gold, 6.5 Duraforce 2 cycle, easy strider self-propelled with rear bag at a cost of $478. I have used Snapper's self propelled mowers for over 10 years and they are great. I don't know much about Lawnboy's self-propelled systems and they seem cheap though I have not tested them. I really like Lawnboys prices but I like Snapper's overall quality of the vacuuming of clippings and the self propelled 6 gear disc. I just think $799 is too expensive for 21-self-propelled mower although it's considered commercial. I will be only using the mower to cut close to my house, on hills, and places where my tractor can't go. I am on over an acre lot and I am looking for something that is durable. Please give me some sound advise as to what to do. Thanks.