I have around 10k sq ft of lawn (or a 1/4 acre) to mow, and it takes too long with a 21" self-propelled mower. I have a walkout basement lot, so while the front and backyards are flat, there are hills between the two levels (max grade is up to 15°). There is also a slope towards the back of the property I was looking at the Troy Bilt 30" Electric Neighborhood mower, but the reviews said they weren't good for mowing other than completely flat terrain. I would like to keep the deck size between 28 to 36"