My husband bought a sony xperia ion 5 months ago and has had nothing but trouble. The phone gets very warm. I turned it off and it did not come back on. Called Sony did not get good help with our problem. They really did not seem to care that much. Called At&t and they sent a refurbished one to us and we sent our phone to them. Well it is acting up also. So we are not happy with Sony and their phones.
We did give feed back to customer care. Was not a good response. Just very unhappy with customer care at Sony and att.
Gbpeery, I can share your sentiments with regards to the heating or warming as you put it. It particularly has low charge retention capacity with the data traffic enabled. But generally, it is a good phone in comparison to phones in its caliber.
Sometimes this can be due to a faulty battery. We've noticed this in HTC Sensation where phone gets hot because of a faulty battery or cheap copy replacements.