Whenever I have melee classes in my group, they ask for this spell by name...actually they demand it and sometimes get upset when they see me casting it on other tanks in the group. It really sucks that this buff costs 12%. Seems like we should receive at least a slight discount for these combo-buffs. But anyways, if you have a bunch of melees to STR-buff, I recommend putting this on the main tanks and put the standard STR-only buffs on the others since they only cost 6%. Keep in mind that the STR-only line actually gives more STR than this line. But everyone wants CON and that's why this spell is so popular.
Yes, this is a lvl 9 nurture-spec spell.