XMG Ryzen can't be compared to Zephyrus. Not even to something like heavy gaming notebooks.
It's not a laptop, but a real portable PC. If I was in a need for one of those, XMG is by far the best one out there, simply because it's the only one with AMD chip, and the price is WAY better then anything out there.
But if I could pick between Zephyrus and XMG, I would go for Zephyrus. Simply because I want a laptop, and not a desktop replacement. My desktop is at my desk, and only time I will move it is either to clean it up, upgrade it, or replace it. It's not meant to be carried around.
AMD laptop chips could potentially disrupt the market. I mean, not even their top tier laptop chip beats Intel desktop chip. And it does all of that while being power efficient. Thats way more power then I really need, but if it is at the same price I'm paying for the power I do need, I want it.
Lets just hope OEMs use it come next year. Otherwise I will buy one, be it on premium device or not. I have no intentions on paying for lousier Intel chips, and paying a premium at that as well. Just like Apple discarded butterfly keyboards because of backlash, Intel can learn the same way.