DFAC is total garbage if its still ran by the military...If its ran by civilians ( like MacDill's DFAC is ) then its fine...Local foods are generally safe...Ask around from seasoned guys where its good to eat...Travel up to Osan to shop and hit up Fogo De Ciao ( trust me once you try this spot, you will go back )...I am not too familiar with a lot of places in Seoul, just stick to where tourists/GIs hang out at and you will be fine...CID does keep an eye on Seoul so be careful not to communicate with any prostitutes...Simple conversation can turn into a world of trouble, trust me when i say that...Eat, shop, have a good time and mind your own business...Oh and never travel alone