I really really want the Optimus G Pro....but......

There is a few things that bother me or will bother me...Has anyone used it? I looked on Youtube for a review and all the review don't mention one of the most important things on a phone....SOUND...

I want to know how good is the DAC on it...and the back speaker..I have a friend that has the Optimus G and the back speaker is very low..Also heard the DAC is not that good on the Opt. G..it sound low...Has anyone tried one at a store or import store? Or a friend that has one? ALSO..Bothers me is the LG updates...Is LG good at updating their phones?