There is no comparison on cut speed between the benchmark vs 3m/norton zirconium or ceramic. The real deals are easily 2-3X as fast and last twice as long.
For non-commercial work, the Benchmarks are fine. They are under $2 ea on sale vs up to $7 - $10 for a 3m or norton. They aren't slow enough to make you hate them, but when you're used to something fast, it obvious they're less efficient.
I run high HP (3hp/75cfm) pneumatic 6k rpm grinders instead of the typical 12k electric jobs. The shavings when using quality discs look like tiny drill swarf (blue metal curly ques) vs the black powder dust most are used to. The difference is cutting vs rubbing. You can tell the cheapies are coming apart faster due to all the fluff floating around while you use them. They start losing chunks at the edge at about 50% wear, which speeds up their death as the bad spot keeps getting bigger.
The 3m has less material, but wears better
These are both about the same amount worn, but the 3m will still cut almost as well as new. The Benchmark requires a lot of pressure on the grinder to get any kind of cut rate without just rubbing as they wear. See the edge chunk missing.
Atlas Copco LSV38 6600rpm. Almost impossible to stall. A top shelf grinder really makes quality abrasives work.
