Speed, mostly. There are blowers that also act as vacuums. It works okay, but still pretty slow, if you blow it all into a pile first. You could do better wi

Speed, mostly. There are blowers that also act as vacuums. It works okay, but still pretty slow, if you blow it all into a pile first. You could do better with a wide device that worked like a lawn mower, but that would only be useful for a fraction of the areas you are trying to clean up.