I use the Mini V9 Nova,
Plus points , more flavour from the juice. Easier to fill but though they hold more they drink it a lot faster than the CE4. I use a 650 EgoT and C and the 1.8 coil gives more punch, good for tobacs the 2.4 is smoother , probably better for fruit. Both work fine on the Ego with comparible battery life to the CE4/5
Tend to use the viva for home and the CE4 for the great outdoors . The juice seems to stay cleaner in the Viva, no need to clean and dry burn so often.
Cant quote the Kangor as I have only used their bottom coil cartos. Did not like them at all but I am sure the clearos are different.