Rolf said, "If you are even slightly heavy handed you will spread the clamps and have to replace the arms. Pegas has resolved that issue with their replacement clamps."
I think he means replace the clamps not arms.
As I see it, the clamp design is the same. Different materials, and they add a lock nut to the left side clamping screw. But the action of holding the blade is the same, turn the adjusting knob to screw down and hold the blade. If you have a heavy hand, I can't see any reason that the clamp will not spread the way the stock excaliber clamps do.
Less vibration, true they are lighter than the stock clamps.
Yes I broke down and bought some. They are definitely better than what was on there - but then again a new muffler is better than the old worn out one too. My EX was used when I bought it so I have never experienced new excaliber clamps to be able to compare them to the pegas clamp. And that I think should be the starting point of a comparison, new vs new.
But I can not see how any issue is resolved in terms of heavy handedness and the spreading of the clamp jaws.