To me the O-16 with it's largest air hole per coil wide open is a tad more airy than the Manta V2 is with just one air hole per coil wide open. Maybe by design... an easier air path in the open O-16 chamber verses the channeled air path in a Manta that can also get clogged some by over squonked joose before it drains. That is how I perceive them with my LDLH's. What you'll perceive may differ.
As for leaking, my experience with them differs from Papa's. I get none from the O-16's air intake holes at all, but do get weeping from the Manta's. Another by design difference maybe. With the Manta's high intakes the weeping is from condensed joose because of my LDLH's. Joose does collect on the top of the AFC between it and the locking cap, eventually comes out the locking caps slots. MTL probably wouldn't see it, DLH maybe not either, but with my very long hits the Manta weeps joose and the O-16 does not. Also may have something to do with my builds. I build large form coils and use a lot of Scottish rolled wick up off the deck (except for the very end of the tails) that holds a lot of joose for my LDLH's. They get huge vapor for the mid sub ohm builds in them that probably also condenses more joose.
All I can think of in the mix offhand. Whether you try an O-16 or not is your choice alone... I well remember the Nuppin' didn't work for you when they work very well for me. Different vaping/build styles.
