Personally, I prefer to collect clippings on my own home lawn. At least after it's established for a year. But for some lawns, it may be very helpful to leave clippings, not due to nutrient value, but to reduce damage to soil structure. http://www.mdvaden.com/soil_compaction.shtml For those who don't bag and leave the clippings, do you do it primarily to save time, save nutrients, or protect the soil? All of those? Other?