I am considering buying a permagreen. I don't want the extra weight, size or purchase price of the z-spray. In talking with my friends who have them they don't use them unless the area is over 10,000 ft at least. They liken it to painting a wall with a roller you still have to cut in the yard with a backpack or hose. What is your experience as far as weed control along edges of drives sidewalks etc using these machines. How much control do you have. I only have 1 very large account I could really use it for and many 4500 sq ft yards and am trying to justify the $5000 expense. If you are using them on small yards have you experienced this problem around the edges.