Shaun,
I have used the gray colored Du-Bro heavy duty plastic arms, and have seen them fail...both failed on the FA-18F elevator servos when I belly landed it in an alfalfa field after a flameout.
The airframe was undamaged except for a few broken landing gear door hinges and the elevator servo arms. A testament to the strength of the design, but since the arms failed, I replaced them with $6.00 Airpower machined and anodized aluminum servo arms.
No more Du-Bro arms for me. An inflight failure could have cost me the entire jet as opposed to the price of a set of hinges from Tam.
Why spend thousands on a jet and go cheap on the servo arms?
Quothe the raven "Nevermore".

Harley Condra
BVM REP
JetCat REP