Hi, Did you manage to resolve your boot loop issue? I have just had this problem, within the last hour! In short, what worked for me was to NOT USE A PC, remove the battery and wait for about a minute, insert the battery back into the phone, press the power button AND the volume down button together, as soon as you see the LG logo appear quickly release the power button and re press it immediately, DONT LET GO OF THE VOLUME KEY! As soon as you see the factory reset screen appear you can release both buttons. Now use the volume key only to select the option to reset and press the power button to say yes, and the phone will be wiped and the original version of Android that was on your phone when purchased will be put back on. Now follow all on screen prompts to get the phone set back up, as you done at new. Setting wireless up is usually one of the first options to set up after your location. You will soon notice that LG will send you the OTA Android software update, you can pretty much ignore everything else and just concentrate on the Android update. Now, although this may seem very odd, you may well notice that as soon as you think it's completed, you will get the LG software update available again! This is actually normal, weird but normal. So just activate this update again as before, this will likely happen for a third time, after which you will be sorted! Without trying to get too technical, this is due to a variety of previous bugs within the software, the only way to get through it is for the whole update process to be split into three downloads, the first time acts as a kind of patch, a platform to enable the second part and subsequently the the second patching ready for the third.
It takes a while, but my phone is now sorted and running fine, with no more looping. The update has now given me Android Version 5.0, Kernel Version 3.4.0, Software Version V20g-SEA-XX.
Good luck, I hope this helps anyone else that's having issues.