One or the other, all about the same I suppose.
Pros for the zpacks zero would be: little under half the weight
Pros for the Newt would be: sternum strap by default, slightly more comfy shoulder straps, 200 ci more room, and you could abuse the material a bit more.
The Newt has a roll-top buckle top, the zpacks has their standard cord closure system.
From a comfort level, the Newt is probably a weeebit more, but honestly, all about the same at these weight levels.
If you care the utmost for grams saved go with the zpacks zero.
If you are willing to give up an extra ounce or so for a heavier closure system (plastic buckles weigh more than cordage) and you want a bit tougher material, go with the Newt.
In the end, there is pretty much nothing anybody can do to a sub 8 ounce backpack to make it stand out among the rest.
If you do not like the wait times of either MLD or ZPacks consider the HMG Stuff Pack. I have used it too. It is a nice solid design like the Newt and Zero. From a comfort factor I would place it at the bottom of the list of the Newt/Zero, because of the shoulder straps which I just did not like, but it was a solid pack that handled the same loads that I use in my Zero.
As for features that I would consider adding... hmm. Well no not really. Once you reach the point of being able to use a backpack of this size, you usually got your stuff figured out and that usually means 99% of your gear is inside of your backpack. If you do not keep your compass/whistle around your neck, you can easily attach it to the Newt, but you might have to have zpacks add a tie-out for your compass cord (unless you enjoy attaching it to the shoulder strap daisy chain, which I do not, but you might).
As for photos... sorry, hard enough to be a sul/xul hiker as it is without lugging around the weight of a camera. Think I have carried a camera on maybe two or three of my hikes over the last three years.