these look like very nice salters I'm gonna get one one day

On fine gain salt mixes the SHPE2000 (newer round corner box) does not vibrate the material well resulting in poor flow. Been fighting that issue since I bought it 3 years ago. Medium to large gain size salt , the material flows well. and my baffles are all the way open. We have watched holes form in the salt material where the opening to the auger and no material drops down with the vibrator. The "OLD" SHPE1500/2000 (square box) works awesome and the vibrator is mounted on the auger tray.  The one I have, the vibrator is mounted on the plastic box body with a small square plate. This design is not transferring the vibration adequately.  This has been my pain for 3 years now.

I bought mine last year as biggest piece of shit doesn’t even spread sand on a 50-50 mix that only a yard and a half was totally bridging not enough vibration very narrow auger