low ohm =/= easy to drive.
There are 20-ish ohm headphones that needs vastly more power than 600ohm headphones. Correlation some times, but causation, absolutely not.
To get a nice volume out of the 6XX, I needed to max out the G6 volume. If you think that's enough, well, I dunno what to tell you. Literally no headroom. So I'd definitely be cautious about what gear you have. You may find a G6 alone to not be enough.
I'd practice caution. Yes, easier to drive headphones should be fine for the G6 (and maybe the G5). But if you own multiple headphones, make sure they're not hard to drive.
I was simply stating my headphones and headsets are under 50ohm & easy to drive. Simple as that.