I have an early model H815 as well, no problems. I am always leery of threads starting with pure speculation stated as 'fact'. There have been a number of people reporting that their phones got stuck in a boot loop, but claims that those issues a due to a hardware problem are pure speculation, as are claims that "any G4 manufactured before [insert random month of the year here] is affected". Look at any Nexus phone or tablet forum on xda and you'll see posts complaining about boot loops after every round of OTAs that Google makes available for their own devices. Many people with Nexus 7 (2013) tablets, for example, had this same problem with almost every version of Lollipop. This is a rather common problem on recent versions of Android and occurs on a wide range of devices and the commonailty seemed to be OTAs that went wrong somehow, not hardware. The more tech-savvy Nexus users tend to fix that problem by wiping their devices and flashing a full current factory image, and then proceed to root them again and add custom recovery images and what not. That process is not quite as straight-forward on non-Nexus devices, but various tools are available. In the case of the G4, you can initiate a factory reset from inside and outside the OS, use LG Bridge to flash the current system image, or use LGUP to wipe and flash the current ROM onto the device.