The write speed on the Torqx shows that it's not really comfortable with the workload, is there some cleaning you could perform.
If you run a typical benchmark, how does it perform?

I wonder if there are factory marked bad blocks on the other drives, the m4 carries that attribute as well as a few others.
What I'm saying is that a few bad blocks is not the end of the world.

Some of my C300s, m4s got a lot of bad blocks and they were already there when I got them.