I grabbed the Nokia from an AT&T store as well. It is kind of weird that you have to put the phone kind of low on the charger to get everything lined up (i.e. the center of the charger needs to align with a spot higher than the center of the phone), but once you get used to that, it seems to charge pretty well, and I haven't noticed any heat issues other than a mild warmth.
The only bad thing is that since the Nokia shuts off when the phone is charged, it messes with my Tasker sleep profile which shuts off the ringer except for specific contacts if it is night time and the phone is charging. Once the charger shuts off, it triggers my exit task and turns the ringer back on!