Interesting survey from Europe
"When asked about the three most negative aspects of ecigarettes (three fields, 154 comments), respondents complained in particular about the poor quality of the devices. They also reported that that ecigarettes were difficult or impractical to use (e.g. "it is difficult to refill the liquid"), that the dosage was difficult to adjust (either too high or too low), that the liquid can leak out during use, and complained about the lack of information on the composition of the vapour and any health risks associated with ecigarettes (Table 4)."
BioMed Central | Full text | Electronic cigarettes: a survey of users
"When asked about the three most negative aspects of ecigarettes (three fields, 154 comments), respondents complained in particular about the poor quality of the devices. They also reported that that ecigarettes were difficult or impractical to use (e.g. "it is difficult to refill the liquid"), that the dosage was difficult to adjust (either too high or too low), that the liquid can leak out during use, and complained about the lack of information on the composition of the vapour and any health risks associated with ecigarettes (Table 4)."
BioMed Central | Full text | Electronic cigarettes: a survey of users