I will say I don't go to KFC all that often. The times that I have gone there I have been pleased. Some times the lines are long but that is to be expected. KFC is pretty clean both on the inside and out.
I have had an occasion where I got takeout and got about a block away and then checked my bag. When I did I noticed that one of my side dishes was missing. I was pretty annoyed at having to go back, but when I did the cashier was pretty nice about it. She apologized and gave me the missing dish.