Well, i dont have balanced cables and headphones to test the balanced output of the Q5, from what i have read is that the balanced output has better channel separation in compare with the single ended output. This will give more space and it might sound more alive that way. This...and it has 2x more power on the balanced output. If its because the power, A5 has more than any amp module.
Headphones are on first place however, i agree fully.
Another thing is that the Q5/Q5s has better frequency response with any amp module than the A5. So if you play hi res audio with 96Khz music, this will be noticable better on the Q5. And headphones needs to have the range as well. A5 is from 20hz-20khz The headphone output of the LG might be limited to 20Khz, and if you connect something with higher frequency response like Q5 to use as DAC, it will sound different.
Any DAC/Amp combo is better than the phones, but phones with better Dac chip in it, like this LG above, its a close call which one is better. I have tried over the years different setups, phones with somewhat better audio and speakers than the common ones, like Sony Xperia Z3, HTC M8 back in the day, Razer phone 2 as well. Fiio DAPs from the X5 serie and M9. One on one, no EQ, the DAPs have more dynamic sound, but once you install something like the USB Audio Player Pro on the phones, Neutron or so and connect this to a DAC, its really close and subjective which one is better. Difference in sound quality usually comes from the frequency response range and what files are being used. Thats in my experience.
That being said, i dont think the guy is missing anything. Yes, the Q5s will be better used as DAC, but if you dont have the balanced cables, or start adding amp modules to the thing, its really in another price range. Its if one of these "dedicated" music players are used on the phones, they are better than the stock players, that really closes the gap. The ES9228 chip in the LG should be on pair with the AKM in the Fiio.
I believe that. However, the question is whether it's an upgrade over v30 + A5.
All this said, if you are looking for upgrade, now or later, i would look the Chord Mojo. If you dont need the Bluetooth, i found it to be better than all this here. It is with lower price s now as well than what it used to be.
And of course i wish you happy new year celebrating guys.