Hi
Tbh i experienced leaking with these coils in the Vinci and the Navi so its 100% the coils. Some were worse than others but Red (reviewer) didnt have any problems at all.
Dont get me wrong they are great kits, flavour very good but for me the coils didnt last as long as others and most leaked, not condensation but actual juice. It did not stop me using them i just had to check it a few times a day and as i said not all leaked.
There are some tips, dont fill to the top, blow threw the mouthpiece and wipe excess juice from the base of the coil after filling, that helped a bit. My bff still uses hers everyday and loves it, she gets occasional leaks.
So it is up to u x