I have a couple setups, trying to figure out what works best for me:
-Juice - A few,but favorite so far is Anchors Aweigh from BRV (Bottle Ready to Vape)
-Battery/Mod - Basic Ego, Vamo V5, and generic Mech Mod
-tank/RDA/RBA/Genisis (model) - disposables on the Ego, Nautilus on the Vamo, drip tip on the mech
-reason for using (dead battery/favorite rig/at work or in public/testing it out/change of pace etc.) Depends on situation, the ego is the most discreet, the Vamo has the most options (and the Nautilus has the biggest tank), and the mech/drip tip probably has the best taste puff for puff, but its a drip tip (not drip tank) so if I'm out and about, its a bit of a pain to keep redripping.