I saw them being used by Uncle Ted on TV.
Unk Ted gets checks regularly from a lot of sources, lol. I saw a vid of him w/
TWO sets of limb savers on each limb. Be willing to bet my Y-25 he turned whatever model Excal he had into the next one down the list power wise. Not to say they don't have the power to spare, but according to posts by Bill T, the loss of fps is significant.
Going out on a limb here, [pun intended] but I seem to recall it was around 15 fps. Using the 'rule of thumb' formula of every 5 gr arrow weight change equals 1 fps.........well do the math on going to a heavier arrow.
When I 1st got the black vix that became Smokes 'Miss Vixen' it had them on it and one promptly fell off. I 'sawed' the other one off w/ dental floss.
YMMV.
My son happened to notice I had lost another Limbsaver off my Vortex Crossbow. I had lost one earlier in the season when it almost took my eye out. It flew off during a practice shot in the back yard.I called Limbsaver and they told me that the "High Powered " Crossbows were giving them some problems.They offered to send me some replacements. They also mentioned they were coming out with a new Crossbow product in 2011. During the very long wait(3 or 4 weeks) for the replacements I did not have the oportunity to take a shot at a deer. Turns out that was a good thing. When I recieved the replacements I installed a new one on the left side of the bow.Still no shots at a deer.Somewhere while hunting I lost the right side Limbsaver. When my son noticed it, I decided to shoot the bow at a target to see the effect of having one Limbsaver on the bow.I was almost off my large Yellow bag target to one side! Lesson learned. If you loose one of these and you want to keep hunting,peel the other one off. Limbsaver sends you 2 replacements anyhow. Dont count on the accuracy of your Excalibur if you don't have both of these installed evenly and securely or removed all together. 
