anyone on here use one? The most common one i'm finding (forestry suppliers or northern tools) is an earthway. They suck, i'll never buy earthway again. Most of the ones I see are seed spreaders, and I'm worried theres no way to calibrate them, like there either wide open or off. There's one called bumper buddy that holds 100 lbs and mounts on the rack. Looks like it'd be alright. Anyone have one? I can get a new one for $160. Recommend another one?