Thanks for further commenting!Yeah, pretty much. The R70X and Planar are a step-up for vocals over the Zeus. And yeah, if you're more sensitive to parts of the treble, Zeus wouldn't be a safe bet.
For my "grainy" comment, I'm not sure if it's the same thing as what other reviewers are talking about as I usually hear them use it in reference to the treble. I was just kind of trying to describe the texture it adds to the sound. If you want to hear what I mean, open up an EQ and try bumping up the 1-2khz areas and see what it does to female vocals. It's not extreme, but there's just a slight hint of it in the Avantone's stock tonality.
In terms of all-roundedness, I'd say R70X > Planar > Zeus. Zeus is definitely more picky, I actually like to use it more with orchestral stuff. The Planar is less versatile than the R70X just because its tonality is darker. Like I said, this makes some instruments sound blunted and too hard to make out if they're in the background. But if you EQ, yeah the Planar works for all sorts of music.
I'd say the Planar resolves better there. The Zeus has more presence and clarity in the vocal regions than the Planar's stock tonality, but the Planar still manages to have better texture and detail with the vocals. And that imaging presentation is pretty unique, I've heard very few headphones that can precisely place vocals like the Planar does.
How do you find the comfort between them? It seems the Planar has more shallow earpads which may be a problem for me, as my ears aren't particularly flat. It might also be difficult to find suitable replacements. Any hotspots on the top of your head? The R70X is supremely light and strangely enough, I don't mind the earpads despite being small, since the headband can easily be bent to adjust pressure