I guess I was under the impression that the slit seeder I rented was self-propelled. Boy was I wrong. That was one heck of a work out. Something I never want to do again. My lawn was cut short, about 2.5 inches, but I guess the thatch was pretty thick. It felt like I was trying to push a stroller through sand for 4 hours. I got almost a 1/2 acre done and I just couldn't do any more. I ended up going backwards and then forwards for each row as it was nearly impossible to just push it straight forward continuously. The only good thing is that it acted a lot like a de-thatcher and I got a whole bunch of dead grass and crap out of the lawn. For future reference, does anyone know if they make a self-propelled walk-behind slit seeder? It almost seems like it would be better to dethatch and then just overseed? This was some serious frickin work that I wasn't expecting, haha.