OK, here's my perhaps final update on this.
everything arrived in mail. Bought a DeWalt metal cutoff 14" wheel but saving it. Instead, used the harbor freight dealy to cut a bunch of 2" thick steel tubing (walls about 1/4"). It worked as advertised, nice, smooth action. The wheel didn't even explode like I thought it would, being harbor freight junk, so I was duly impressed.
I then went out and bought a 14" diablo masonry wheel 1/8" thick. I cut a brick in half with it but was disappointed at how long it took to slice thru, even though it did the job. The dust cloud was enormous but I'm working outside and the wind was just right. My diamond wet saw would have gone thru the brick about 3 times faster.
But I bought the thing to cut steel so I can't complain.
One thing I noticed at Home Depot (where I just got my diable masonry wheel), is that the dewalt and other metal cutting chop saws have a much heavier base, perhaps cast iron. Hopefully the innards of the HF model are adequate. It did come with an extra set of brushes, which I have no clue how to install. Maybe I have to look for the instructions LOL. Anyway, the extra brushes indicate to me that that's probably one of the first things to fail.
I'm unsure how long brushes are supposed to last and what makes them fail.
Also, I don't know if the more expensive model metal chop saws have special brushes that never fail.
Later
DaveV