For some of you who are not seeing the server loads, check that you are in the usergroupid 6, which is the admin usergroup by default. But if you had made another group with a different id number as admin, the hack won't show server loads for that group. To fix that you can then edit the xml file to change the 6 to whatever your admin useridgroupid is.
Also see this post where I figured out a way to show the server loads to all usergroups:
https://vborg.vbsupport.ru/showpost.php?p=841699
Has anyone tested this hack on vBulletin 3.6? Please post here.