No problem so far playing the game, it exits fine, goes back to XMB never froze, never beeped. using an old fat 80 GB that was bought in 2010, a bit before GT5.
As I read all the stories with this, many people did some kind of a modification to their units ( either upgrading or prevention reflowing because people heard of other stories) before it crashed when using GT6.
I'm not sayin that everyone whose game reboots is in that situation as I have read people having stock fat units to exhibit such behaviour, but I guess that modding in a way the unit jinxed it.