I've noticed that the phone feels significantly hotter after making calls of 20+ minutes. Hot enough that it's somewhat painful to hold my hand against the back. Two questions: Does it only feel hotter because of the glass material conducting and maintaining the heat better than the plastic back of the 3G/3GS? If it actually does run hotter, could utilizing a case actually contribute to overheating the phone in situations that it otherwise would maintain a working temperature naked? Unrelated: The iP4 may not appear to have a better quality signal, but my dropped call rate is FAR lower than with the 3GS. In fact, since I began holding the phone correctly I can't even remember the last dropped call that didn't occur intentionally.