Cos: Boge is the manufacturer. There are other manufacturers also, such as Bauway. Boge cartomizers are distinguished by a silver colored connector and two air holes. They are the only cartos I have used personally, after reading much on ECF, and I like them a lot, I just ordered more.
Some people like the Bauway just fine but they
may have a shorter life expectancy or higher DOA rate. I recall reading they have only one air hole. So if you like a harder draw you might want to try those. You can tighten up the draw on the Boge simply by screwing them more tightly onto the battery (which blocks the air holes slightly).
Cartos, compared to the cartridge/atty combination, hold more liquid so they last much longer (2x-3x vs. cartridge), don't leak if you don't overfill them (read up on various way people do that) and taste fine to me. There are too many cartridge filler
mods to compare to (I have mostly used the blue foam). Cartos allow you to quickly change flavors without any odd transitional tastes between different liquids, as occurs with atties if you don't clean them between changes.
My original cartos have been going strong for over a month without cleaning, I have been using 8 in rotation so far and simply refill when they seem dry. Apparently they last longer that way. My oldest ones now seem to want cleaning, the taste is going "off" a bit. Some people only fill them 1x-3x and then toss 'em.
I recommend you order a few and try them sometime. James offers them singly at a great price. Other vendors offer them in boxes of 5.