Computer OS: WinXP sp3.
I've been reading threads/discussions for a few days now, researching before I jumped into rooting my new Moto G. Finally I chose to use the first method outlined by @paulobrien here.
This gave me root but wouldn't allow for superuser installation for properly monitoring/regulating root access. I tried multiple times with different methods and still just couldn't get superuser to install. So I tried the second recommended method.
Everything seemed to be fine as I went down the list until I followed these instructions:
Run the command 'adb-windows sideload supersu.motog.zip'. You'll notice the installation complete on your phone.
wipe cache partition
Whether Motorola are really kinda inept/rushed, or if it's meant to sorta discourage people from playing with the phone's innards is anyone's guess. Whatever the reason, I copied supersu.motog.zip from my r1-motog-modifiedrecoveryroot folder - kindly supplied by @paulobrien - and boom! I have a properly installed and functioning superuser.