The amount of heat generated will depend on the degree of battery discharge before charging it, how low you allow it to get before you charge it. Considering that some have no problem while others, even that Engadget review, mention it getting too hot to touch, it's either a case of different hardware being used for the charging circuitry, too high of a voltage coming out of some AC adapters, or radically different states of battery discharge levels when charge is initiated.
Another reason for the different charging temperatures being reported could be this - typical USB ports are current limited to 500mA (1/2 amp) while the special high current output USB ports on some PCs will output 3 amps. From one reference I've found on the net, your tablet's AC adapter outputs 2 amps. That's four times higher than the 1/2 amp coming out of a typical laptop or desktop PC's USB port. If you charge from that typical USB port, it will be artificially limiting the charge current to a maximum of 1/2 amp resulting in much lower heat generation in the charging circuit in the tablet, but taking more time to charge due to the much lower charging rate.
Yeah, I understand stand the USB specs, have discussed them in many threads, on many forums, including this one.
Bought mine on day of release, rooted it, and use it about 6 to 10 hrs a day.
I Recharge with factory charger, from as low as 8%.
Never had a problem with heat buildup.
Your right that it could be different components, or assembly issues.
Just speaking from my personal experience, with mine.
Electronics are far from being cookie cutter devices, each has a separate personality.
That's obvious from reading any tech forum
Sent from my SCH-I535 using AC Forums mobile app