i notice that the back of this device really gets warm when the device is in my pocket and not really in use. not hot, but just warm. so far i am liking the device. i was out of the country for a few days and since i wasnt using data while roaming i locked it to edge and was surprised that the voice quality was really good and when i did use a little data (google maps) it seemed pretty quick over edge. satellite lock times is usually pretty fast too. i had it set to geotag photos, and i found that if i was indoors and put the phone back in my pocket before it got a satellite lock it would keep trying to get a location lock for at least several minutes. that could be a bit of a battery waster.
the maps app seems crippled without using data as each time i tried to look up an address it would try to go online, even though i had loaded the entire state of arizona with the maploader before i left home. luckily i had installed garmin xt and it worked well.
i found that listening to mp3s sounded fine at full volume, no crackling from the speakers. the only time that happened was when i was using internet radio at home and the station had a low quality feed