The weight of the Atlas in your link is definitely impressive. I guess the Tuffline disc that would be comparable to that one would be the line made from 4"x4"tubing, while the Atlas is 5" angle iron. That is similar to the lines that I compared. My Tuffline is 4x3, and my Atlas is angle iron, though I don't remember the size. It seemed to me that the tubing makes for a stronger disc, but part of that perception may just come from the fact that my Atlas is worn out.

I think you definitely need to compare the thickness of the blades. The Atlas must use heavy ones if those listed weights are genuine. I found that info hard to get; I had to call them and ask in a couple cases. One thing I do remember is that the Brown had the thickest blades of any of them. Of course, it was also the most expensive.