18 series vs 26 series Mech Mods?

[epat6000]

Hey, so I am just getting into mechanicals and am finally figuring out what all the hubub is about. I currently own a VAMO using 18650's and a Seven 22 using 26650's. I have always only used regulated devices but am venturing off into the mech world. I have my mind set on either a Panzer or a Hades (from my research, they both seem widely loved and durable). I have seen Panzer mods in both 18 and 26 series models and the gorgeous Hades in just 26650. I have both series batteries and I know my 26650's last a lot longer, but what would be the better go to for a mech mod? I currently am building single 1 ohm micro coils on a Russian 91 on my Vamo and .7 ohm dual coils on a Tobh 26650 Atty clone on my Seven 22.

I understand the reason for having a mech mod, but what would be the pros and cons over one battery series vs. the other on a mech. (size is not an issue for me)

ps. I understand the pro's of the copper 510 contact pin (less voltage drop), but is there a true advantage in an ALL copper mod or is that just for looks/a gimmick

Thanks a lot!

 

[MrPlink]

Only con to 26650 is the size. Outside of that I dont think anyone would claim more mah is a bad thing.
You can also get inserts that allow you to use 18xxx bats.

All copper construction is more likely to have better conductivity but the differences are fairly minute. Generally nothing you cant get around by simply making a hotter coil UNLESS you are a total cloud junky and MuST have every plausible bit of voltage available for your .15ohm coil