I was curious as to whether anybody else has noticed this as well. A friend of mine informed me he used a 6 and it was much much quicker to the draw with Touch ID authentication. I decided to try this for myself, I set up my fingerprint on my families set of iPhone 6 and I set up my finger on my friends 6 plus (as well as used my 6 plus to test). Low and behold, every iPhone 6 unlocked almost twice as fast. I don't notice this day to day, I just thought it was weird. I'd love to test the 5s as well, however I'll have to wait until the end of the week to give that a spin. Has Apple acknowledged this was a bug? I wonder why this happens.