ORIGINAL: SAVAGEJIM
+1 on the RPM arms. They use superior nylon; they use high quality PolyCarbonate nylon and those will take so much more than the stock HPI plastic from Taiwan. Also, they are more robust than alum arms as well.
The original plastic from the Savage 21/25 was very similar to RPM's nylon, and darn near indestructible. However, I agree that the new X plastic is markedly inferior.