I have never seen one but I almost fainted when I found out how much the tailgate spreader was $4,000 .I thought that it was a little steep for such a unit.If you buy the whole set up from truck craft it will run you $8K .
I have a truck craft insert(steel) and an easy dumper spreader modified to fit the truck craft insert
the truck craft spreader is alumnium and yes it is expensive plus it spreads at one side much like an under tailgate
the "easy sand" as it is called is steel and half the price, we use it a lot and it works well, the spread pattern is best when bed is lifted a bit
I already had an insert and wanted to go to bulk salt at the time so it worked good for me. If you do not already have an insert than a v box alone is cheaper for a single purpose unit and i think a v-box spreads wider...we have both now this will be the third season with it and replaced the spinner motor and some bearings ... basically minor repairs
I answered this in the previous post titled "Spreader for my dump insert..."
Even though my spreader is to the driver's side of the vehicle, I have never had a problem with the pattern. It does predominantly spread to the left, but I get full coverage to the rear. I have even seen salt hitting the ground and things to the right. Are you sure your spinner is adjusted correctly?