I have used 3 out of the 4 ways so I will take a shot at your question with what I know....
I got my eGo
tank about a month and a half ago, and after a week or so transition time I stopped smoking and uesd the eGo exclusivly.
there are 4 basic ways to use a eGo
Atomizer and Cartridge ( standard eGo )
Tank Atomizer and Tank ( eGo-T )
Cartomizers
Dripping
The tank requires a different kind of atomizer, which will not work with cartridges or for dripping ( unless you alter the atomizer which I have done once )
The Atomizer and cartridges come in type A and type B, the type B's are huge ( cylinder atomizer ) and so are the cartridges ( this is what I am using now )
Type A are cone shaped ( you need a cone to go over the atomizer ) and are basically standard 510 atomizers
For dripping you can really use almost any atomizer ( except the tank unless you modify it )
Cartomizers ( which I have not tried yet ) are a cartridge and atomizer in a single unit.
The great thing about the eGo is that these individual parts are not very expensive, so you can try a lot of different things with an eGo kit without spending a lot of money.
My current recommendation is for a standard eGo ( or Riva, an eGo knockoff at Liberty Flights that is less expensive and fits all eGo parts ) I started with the tank, but they are a bit fiddily and so I am actually recommending the standard eGo.
However my wife still prefers the tank, and the tank did indeed get me off of cigarettes so I am not going to put the tank down.
Don’t worry too much about getting the wrong system, ( tank or not tank ) cause if it very easy to try different things. But you cannot use cartridges with a tank atomizer and you cant use
tanks in anything but a tank atomizer. That is the bad news, the good news is that a different kind of atomizer can be had for like $10 and a pack of cartridges are really cheap, Cartomizers can be had for 5 of them for like $16 so you aren’t spending a lot to try different things.