I don't disagree that Cupti does provide a certain level of flavor, but I do believe it is somewhat muted and the restriction evident in the CLOCC coils makes the experience for airflow and flavor delivery sadly lacking in comparison to Nebox. While it does not leak and I have not had flooding issues, I would much rather tolerate some minor oozing from Nebox When I charge it upright and neglect vaping off the juice expansion while the battery heats the tank & expands the juice in exchange for the flavor, airflow, capacity, and vape quality I receive in relation to Cupti.
I maintain 4 Nebox in rotation and own 6 (2 backup). I own at least one Cupti(2), Plato(1), Summa(4), Egrip II(3), & many earlier Egrips(6). Nebox still tops my list as the Best all-in-one I have ever used and the best currently available although I have a lot of respect for the Egrip II when used with the Notch Coil and a proper Anti Spit Back Drip Tip such as the one from Aromamizer. If it were not for the spitting, juice capacity, and battery capacity issues Egrip II would be the best all-in-one on the market. Evic AIO corrects the Battery issue & tank cleaning issue, however juice capacity & spitting will remain but the flavor should remain outstanding. Plato lacks capacity, suffers from a messy fill, and almost a complete lack of TC Coil availability. Summa provides good flavor in a very versatile design but is hampered by a company that cannot field adequate coil availability, refuses to incorporate DNA75 in a parallel product line or explore the bottom airflow coil & RBA configuration possibilities their design offers to make the device the market leader it could easily be.
From my experience with Cupti, if people are plagued with flooding, there is either an issue with one of the two o-rings sealing the tank or coil due to user error thereby compromising the vacuum pressure of the tank, or Kanger wicked certain batches of coils poorly during the manufacturing process.