Looking at buying two of these. I've been told they will dump regular bagged salt from job to job while the spreader is off. How true is this? I've read on here about a gaurd over the spinner end of the auger, does this help? I know they have a nice screen on the top to keep clumps out, but how does the auger handle any clumps? Do they just sit on top of the spinning auger, get broken up, or jam the auger? And lastly, how does this spreader compare to the Western Pro Flow II? Thanks in advance.