before replacement i was in 4.2.2 only for about 5 days (I had checked software updated but it was showing latest already available) and even the replacement device had 4.2.2 and upgraded to 4.4.42^^ What do you mean "upgraded to 4.4.2" ? Didn't your unit come with 4.4.2 out of the box? My unit came with 4.4.2 and also the same is mentioned as the OS version in the spec's. But in any case, I did not face any heating issues in my limited usage so far (which is mostly benchmarking and some video playback). The back did get slightly warm, but its same as my Galaxy S3 and no where as bad as my Galaxy S.