Wow what pv are you V4L people using. I have stayed away from the cartomisers because they cost more but my 901 is way to smooth for me. After hearing this I am thinking I want one of these.
Cartomizers are a bit more pricey, but they can easily be refilled - some have refilled up to 20 times. I love the vaporking - and V4L can't be beat for customer service and extra goodies! If you have any doubts, just read the V4L forum...