The only real hurdle was getting used to the change in how you use it versus smoking. With smoking, you have a cig, get a massive dose of nicotine, and then it tapers off in your bloodstream over the course of the next hour, leading to that craving for another dose. It's a stimulant so I'd feel a bit cranky and foggy until I had another smoke.
With vaporizers it's more like a hookah where I just sort of puff on it throughout the day, getting a lower yet more steady dose. It took a bit of getting used to but it was entirely more effective than any other nicotine replacement I'd tried. More importantly, it was still enjoyable which is something the gums and patches and sprays miss.
Since then, I've lowered the amount of nicotine to barely anything (maybe 2-3mg/ml) and read up on how to mix up the liquid so I'm not spending a fortune and I know exactly what goes into that mist I'm occasionally inhaling.
I hear so many comedians and read articles where people make fun of "vaping" as super lame and uncool, but I never gave a shit about that to begin with. I just accepted that much like my morning coffee, I like the bit of mental stimulation provided by a bit of nicotine and am thankful that I don't need to inhale tars and carbon monoxide and particulates and all the nasty products of combustion in order to get it. The idea that this is a "cool" thing the way some insist that smoking is just makes me shake my head.
RE: the disposable cartridges, I could never really get into that either. I don't like the waste or the cost and always gravitated to the things I could just fill up myself and maybe swap out the wick every week. I'll always spend that 5 minutes a week to avoid buying and tossing packs of plastic bits every couple of days.