The "hybrid" has two different batteries. One short battery that makes the device smaller and more like a supermini (pee wee). One longer battery that has better capacity and makes the device longer like a mini (901 or pocket mini). Other ecigs have two batteries the same size and fit one category or another.
Whichever model you decide on, spare parts and liquid are a must.
For your question about dripping and carts: Dripping usually means putting liquid directly into the atomizer and using a mouthpiece with no filler in it. Using cartridges, you can either use prefilled cartridges or fill your own. Dripping gives a more consistent throat hit - you might find that real important coming from Camels - but does have more risk of running the atomizer dry, getting the battery wet, or voiding your warranty, and does require you to stop more often to supply it with liquid. Using cartridges has its advantages and disadvantages too. Please read the forum, you will find lots of useful info.
