So I ordered these coilovers for my 14 FiST, had them installed the same week they came in. one regret I have is I did not order the protector sleeves with them, but I don't ride this car in the winter either way so there is no corrosion on the body of the coilovers yet.
One issue I am still having is a good set of sway bar end links as the stock ones will no longer fit if you adjust the ride height, but that comes with all modifcations you do to a vehicle.
Over the years and a couple autocross and track days, I have put about 40k miles on this set and haven't noticed any deterioration happening in performance or finish. The ride for the "Street sport" is about the same firmness as stock, so your not losing what little comfort these cars have stock but gaining so much adjustability that you can set how you can lunge into and out form corners easily. If you take high speed corners hard enough (with my preload setup) you can still 3 wheel these cars which is pretty normal in the Fiestas and some focus setups.
Overall I am very happy with the entire setup and would highly recommend to anyone wishing to upgrade from stock to get more adjustability.