I disagree with the statement about Cartomizers help with flavor, for me it is directly dripping into the atomizer for best taste. Cartomizers and
tanks are great when on the move (don't drip and drive). I would look into some of the more premium juices from online vendors like: FreedomSmokeUSA (freedomsmokeusa.com) or Ms. T's Bakery (mstsbakery.com). If you are "underwhelmed" with the nicotine levels, adjust them (I use 30mg atm). If you are unhappy with the smoke produced (adjust your levels of vg (Vegetable Glycerin). I first tried an e-cig (green nicotine) nearly a year ago and found it to be a horrible loss of money and time (made the mistake of buying from a mall kiosk).
Find what works well for you, I would personally recommend using atomizers and dripping directly (if you are able), or invest in a good
tank mod (liquinator works well, madvapes.com has some great
tank mods for like $10). To me, cartomizers are very hit and miss, I get horrible taste from about half of the ones I have tried (i've tried a lot).
Most importantly, don't give up on giving up tobacco products. I quit a 20+ year habit of smoking 1-2 packs a day, several of my friends have quit as well (smoking and dipping) with the use of e-cigs. If you are interested in more information, feel free to message me anytime.