This is a long term review with comparison to similar equipment.
At least 3 years ago, and after many bike camping trips, I've had an aluminum cage Salsa Anything Cage and one of these plastic EXP HD cages, one on either fork leg.
The original aluminum cage has a similar radius but slightly larger radius, perhaps from bending. It has done the same duty as the plastic one. Over time it's taken some hits, hard ones, and of course the regular grind types too. The leading edges have the black paint worn off. The bottom "shelf" is slightly bent down but still holds a load. I could bend it back, but don't, because I figure that would increase metal fatigue.
In contrast the plastic one looks like new.
I just bought a plastic Anything Cage because I decided I wanted a more symmetrical look to the front of the unloaded bike. The metal cage is still functional. I might move the metal cage to inside the triangle of my bike and move the frame bag there.
The plastic EXP HD CAGES came with tough silicone straps. They stretch, a little, but not as much as you might think. They are tough. I think they are too short, because I like to carry stuff that is bulky sometimes.
In contrast, the aluminum Anything Cage came with longer nylon straps that are the length I wish the silicone straps came with.
Altogether the straps, both the nylon and silicone ones, are too fiddly. I really want to swap them with nylon straps with snap buckles.
Compared to the Topeak version these are on par, except you must have the three bolts on your frame.