Well it depends on the usage I guess. I have to say I have never had a spontaneous reboot of my device due to running out of memory. (granted, I am not in habit of just opening applications to the background just for the sport of it, I use what I need at a same time and close them after that. Just as I use a generic computer, really.) Only couple of times I have had a spontaneous reboot the cause has been the same, if the network coverage is really bad, like I am in a cellar and a CS call is ongoing, sometimes when the call breaks it will actually boot the device. I have not managed to get that happen outside ever, only in the same cellar two or three times.