I just sourced this script and played around with it. creating the whole setup is indeed just a matter of some few minutes. first a default skeleton is built. after scaling the skeleton you move each joint individually to fit your character. if done manually all that stuff it would cost you quite some time! also this script provides different Rig Presets from hi- to low- "ControlDensity" which is a plus.

you have to decide for yourself if the creatureTools fit your style of rigging a character. I personally like to set up my skeleton a bit differently from that. e.g do I need more than one single neckjoint. also you have a heck lot of CTRL objects. if you take a look at the hand setup you will notice that there is a single curve for each finger, handTranslation and handRotation. I personally would have subsumed them under one/two CTRL object(s). in addition I prefere a reverse foot setup - but that´s just a matter of taste I guess.

nontheless this is a mighty tool for sure. just try and play for some time. you will see if it is a enhencement for your workflow or not.

kind regards!