Also, you won't have to pay for your Barracks once you get Sun-Tzu's. I prefer it, myself, though I play on Warlord, when the Computer is too stupid to use the units it gains from SoZ/KT effectively anyway. I don't go for many wonders anymore (yay! Off wonder-addiction!), but Sun-Tzu's is one I love, since I don't have to pay upkeep.