So far I have used this 3x and I love the way it pumps easily, holds a tight seal of the pressure inside and the way it sprays.  Some have said that it's heavy, but I've had units which were much heavier.  Hey!  It's got 2 or 3 of gallons of liquid in it and when it's full, it's going to have some weight to it.  Empty, I think it's very light.