5S user here, still on the original battery and original display, but I do use a case which has saved my bacon a couple of times. One of the things touted about this form factor when it came out was that even though it had more screen real estate than its predecessors, the thumb of an average sized hand could still reach anywhere on the display which makes it particularly handy. (pardon the pun)
I'm not sure how much stock I put into these drop tests. I've seen some phones you figured were done for come out unscathed when they hit cement, and others of the same model land on softer surfaces and have a nice crack down the center. I think a 6' unprotected drop is a bit much. Where I work, we occasionally spec out display tests and the device remains fixed so the approach angle (from a steel ball) can be controlled. To me, that makes all the difference.