I first used the Vype epen, however after around a year I found that it was quite expensive to keep buying the refills, as I often went through one a day. I also had a few problems with some of the cartridges, however the Vype customer service team were excellent and sent me replacements with no hassle. I have recently purchased the Vype etank as I felt it would be better value for money. I have only had it for around a day but I am very impressed. Filling the tank only uses about 1/6 of the bottle and the bottles themselves are cheaper so much better value for money. It is also very easy to refill. Far better quality than any other refillable ecig I've used in the past, it is almost impossible to accidentally drop any liquid into the wrong place, it does not get hot with use and the battery life is very good, and no unpleasant e-liquid coming through the top into your mouth. As previously mentioned, Vype customer services are excellent and they are happy to sort any problems you have.