I started also this way, its a pain, your cartomizers will leak after couple of days and you will get tired of it. You should upgrade as fast as possible if you like the e-cig. Buy yourself a carto tank, also upgrade to 510 thread batterys around 1000mAh.
The biggest reason I don't want to do the carto tanks is that I don't have anywhere to keep them when I am out and about. I live in the city and use public transportation for everything and I don't really want to carry a bag full of accessories everywhere I go just for vaping. It might be good for at my apartment, but most of the time I'm not here, and being a college student I don't have a desk I can keep them at while I'm out at classes. I don't even carry books to class, just a binder and pen because I hate having a lot of stuff with me. To me it's a bigger pain to carry larger accessories I can't fit in my pockets.