i know in the past non jail broken phones needed to be on wifi to get high quality youtube downloads. i was on LTE in NYC the other day and tried a youtube video and it was ****** quality(i know there was a high res version). I have ATT, has ATT limited this aspect of my celluar data use like it does facetime or was a ****** LTE connection to blame. i did a speed test afterwards and it was pretty awful LTE speeds.