I've used both, but tend to find sit-on tree stands uncomfortable, and limiting in the area I can swing the gun and shoot. Ground blinds are good, and the pop up ones can be moved so easily. Even a makeshift cover with some camo cloth or burlap strung across two trees or some bushes works well, but depending on the area, may or may not be as convenient. If deer don't see movement, it doesn't matter that the blind was just put there. Deer walk past recently parked vehicles all the time. I've seen deer walk past a truck while I was sleeping in the box, or returned to a car to find recent hoof prints right past it.