If you take a lot of pictures and movies and currently use a pass code on your phone it's probably worth it. Speed wise I notice zero improvement. I guess the 5 was already pretty fast.Since your asking advice your obviously not a Apple Nut like myself who simply must have the latest and greatest.
I say Save up for the 6.
I'm a tech enthusiast and I usually have the latest and greatest. But I also try to do it smart and economically. Do I want a 5S? Of course. But I'm not rich by any means and have a wife and kid, so I need to pick my "battles" wisely.