I have that bow, it is a perfect balance between speed and longevity. Fast enough to kill what ever you can see and not so much pressure on th4e limbs that you have to replace servings every twenty minutes. I did a whole lot of research before I made my choice from Excals line-up.
I agree with Ranger on the Boo string, the only maintenance an Excalibur needs is serving replacement, I am using one of Boos strings now that has hundreds of shots on it and it looks exactly like it did when it arrived in my mailbox.