Well it's not leaked today since taking apart and cleaning (and by that, I meant just unscrewing base, removing coils, wiping down) so maybe it was just user error somehow - but not sure what that error would have been - coil was definitely in correctly etc. As for other threads about it leaking, just google "zenith leaking". And like I said, I did notice the general consensus was that they're leak free, hence why wondering if just faulty tank/coil.
Only thing I can think of is I might have been inhaling (or whatever the correct terminology is here - drawing?) too hard, and this caused too much juice to build up inside coil till it leaked - have got into the habit of doing this with the Nautilus X so as to avoid dry hits, but maybe this not necessary with the Zenith. In fact I'm finding now that just the slightest "drawing" of vapour into mouth is needed while fire button depressed, mainly just let the vapour "collect in mouth", then inhale after - gives bigger clouds too this way, and doesn't seem to be drying out coil. Very different type of draw to cigarette, or even T18e, would people agree?
Anyhoo - if that's all it was, I can happily adapt - and if I don't experience any more leaking problems, then definitely rate this tank highly! Again, thanks for the recommendation.
btw AJT, can I ask why you have 6 of them?? Is it so you can put different flavours in each?