I used to think I didn't need it at all, and that my strength as a warrior was more than enough to take and trade aggro with a fellow paladin. That is, until I got to coil, in which trading aggro between each other was absolutely required. With the slew of new content we have now where two tanks are required(the extreme primals and Ultima hard mode, along with crystal tower), I cannot imagine going without it. It's just too good to pass up, even in cases where there is no second tank. It also has considerable range, so it's useful to pull stuff off of people at a much greater distance than normal for those particular emergencies.