It's funny, when I first started vaping - which incredibly enough was primarily meant to be a money saver more than a health-saver - I was asking everyone I could find how long coils would last, how long one spool of wire and one bag of Muji cotton would last..
In reality, I don't think I've used the same coil for more than a day at most. Not that they wouldn't last, but I always end up just remaking them to see if I can do it a bit better, or just different. And I haven't even started making fancy coils like Claptons.
On the upside, it turned out that my £2.50 bag of Muji cotton will in fact last for months and months

About the only vaping supply that I've bought once and never thought of needing to get more, or better.
Ah, really?

I
love tanks with accessible decks (without emptying the tank), like the Aqua v2 (my absolute fave so far) and now the Goliath - with the Goliath's added benefit of the closable juice control, which seemed awesome.
But yeah I do also dislike small build decks - the Aqua v2s is kind of small and I'm working on my first atty mod to make it much more accessible (post-less.) But now you mention it, even that does seem bigger than the Goliath. In videos the Goliath looked small but not unworkably so, but if it's limited to 2-2.5mm coils then that's a big downside. I can get 3mm in the Av2 as long as the wire isn't super thick and the coils aren't too long . I think my current Av2 build is 2.5mm, but that's 2 x 7 wraps of 3x30G twisted Kanthal so there is some surface area there - and it took me a good ten minutes re-arranging the coils to get the chimney on with no shorts.
When I saw the Goliath deck I thought maybe it would be possible to have a large single nickel coil going between the posts, straddling the two air holes. That would definitely need a small diameter (2mm I guessed), but it could be fairly long so spaced would be OK. Have you tried anything like that?
Maybe I will give the Goliath a miss for now, then. Or rather, order the clone from FT at 1/3 the price. I'm trying to make a rule that I stop buying stuff from the UK unless it's really special, and make myself wait for the Chinese shipping to get it at a vast discount. I was going to go ahead with the Goliath locally because as an accessible-deck tank it seemed special, but maybe it's not worth that after all.
Thanks for the heads up!