Man I'm sorry for the late arrival. If you get any Nautilus get the N2S it's everything the N2 should have been but isn't.
I have much mad love for the Zenith too, both finally have mesh coils for MTL and in my opinion the best coil for the zenith is the 1.6 and I hated the mesh (it was fine until the flavor died off in a few days, could have been a bad coil) but SUPER airy and really in some ways less traditionally MTL,
The Nautilus mesh coil is similarly "more" airy although you can vape it closed down. I like it for flavor, honestly probably the most of the coils (although I am more than happy with the 1.6 or 1.8 too.)
Benefits of Zenith LARGE capacity with good flavor, top fill is super easy and innovative and it's built like a TANK. You can't even strip your threads because they are built into the MOSTER coils.
It is a fantastic tank . The N2S is prettier, nicely designed with an also fairly innovative topfill system, less capacity 2.6 but it's not a juice drinker. It's less tank like but the design elements are really lovely. I think the Zenith is ugly as sin personally, but I (like everyone else) am not buying it specifically for its LOOKS but for it's super great vape and many options.
Unless you are going to get both, I can't really tell you what to do but they are both excellent tanks in their own ways. For durability and just "I can do it it" (except for mesh and I vaped one coil, to be fair I could have gotten a dud) the zenith has the edge.
For the mesh coil, looks and well, some how (in my mind) more traditional MTL vaping the N2S is great.
But, I don't really think you'd go wrong with either. Just don't go with the original N2. It's not a bad tank but the N2S is SO MUCH BETTER.
Good luck deciding.
Anna