Well I am new to salting entirely. We have a driveway that takes around 1,000 lbs to do each time, but have spread by hand until now. It isn't a regular thing that we need to salt...the drive is gravel, and has a great runoff so it clears itself well. It's when we get freezing rain that we run into issues..
Picked up the sp325 from the local dealer.. Was actually going for the 210 that just plugs into factory 7 pin trailer plug, but two weeks of waiting and freezing rain dictated that I get something, and now.
So, came home with the 325, hooked it up, and immediately decided that the factory is wrong on what types of can't cannot be used.
Ran 12 bags (50lbs each) of rock salt, that worked good. That was as many as I could get...everyone is out of stock.
Ran 4 bags of calcium flakes through it (90lbs each....actually leftovers from when we used to need calcium to keep the plaster from cracking in the public pool that I run in the summer). Worked great.
Then ran 3 bags of ice melt, and 7 bags of rapid melt through it.
Everything I ran through it, it fee perfectly with zero issues. I am going to run in and fill it at the local co-op with bulk and prove everyone wrong there, too. I bet it works great.
The only thing I can say is that it is honestly too small for my needs...but we will use it maybe 3 times a year. This is only for my driveway, which is also my business parking lot and drive.
Was new in box but didn't come with cover...that will be here tuesday

Just a happy customer. Thought I would share