Their UB in warlords is incredible - half duration whip anger. I am playing with them now and my farm cities equal my HE city for production of units.
Put one hammer into a unit, whip an axe/spear/jaguar for 2 pop, builds another quickly and only 7-8 turns later I can do it again (on Epic). 2 units every 7-8 turns is great to quickly ramp up for war.
The UU isn't great, but they are fun to exploit. I am running theology at the moment and can build jaguar with forest 2 + cover to rush through to the enemies back lines and take out archers on resources.