I'm not sure if its just me but I kind of prefer the look and feel of the 5C to the 5S. I quite like phones to feel light and plasticy as long as they perform well under the bonnet, and (maybe strangely subconsciously) it doesn't feel so bad after many months of being chucked about if its got a slight scuff or smudge either. I'm less likely to feel the need to buy all kinds of protective addons and worry about the phone looking nice and shiny.
Also the 5S has those 'precision cut' sharp edges. I like the smooth plastic on the SC. Nicer on the hands when retrieving multiple times from ones pocket.