I've done a lot of trial and error on hardware set ups. Part of the fun of of vaping is trying different hardware combos, but it can get expensive (though a pittance compared to analogs). Currently I have a dual coil tank on my Ego passthrough, another Ego with a Boge 2.0 cartomizer, and a small Ego set up to drip with a generic atomizer. The tank (Madvapes 5 ml) rocks, though it is a bit ugly on the Ego. The Boge cartomizers have been the most reliable I've found, and are cheap enough to be disposable, and vape very well. Dripping is the absolute bomb, and if you clean your atomizers daily, they last a very long time. I also have a 5 v boxmod, but I don't use it that often. For reference, I run a 24 mg 555 or RY4 in the tank, a 0 mg 555 in the Boge, and 6 mg fruit in the drip as a pallet cleanser, I alternate between the three setups.
BTW, I've had horrendous luck with dual coil mega cartomizers, maybe just bad luck.