I went with the F5 due to the package of warranty, turbo, creature comforts, price, cvvt, manual, ride quality etc. Plus since we use it for family stuff, the rear heated seats are nice, and the driver begets seat is a must in Texas heat. I have a wrx for when i really want to play though. And wife has a turbo optima as well. So i am biased towards kia.
I have not driven a st but i that is also not the first time I have heard about the seats. I do think the focus looks sharper. Have heard that the cargo space is not as functional. And then there is the ford name. Only ones to not take the bail out, but lots of recalls etc. Kia has recalls too, but i have seen a steady improvement in quality, styling and enguinity. Ford has come as a ways up too.
In the end its about what YOU want and need.