Always beneficial? No, imo. What we Galibier owners have found is that the 6 lb. Anvil seemed to work well with the older platter surface, but it is detrimental to the sound with the newer graphite platter surface. There was too much damping, so the Anvil is no more. And the effect was much as you describe except that the extra "control" was too much. YMMV and all of that.
How much does the Beak weigh? Does your clamp have an o-ring that sits around the spindle? If so, try the Beak with that in place if you haven't already.
How much does the Beak weigh? Does your clamp have an o-ring that sits around the spindle? If so, try the Beak with that in place if you haven't already.