I've only been using the Vype e-pen for a few days now but I thinks it's great. I love the fact you can change the flavours and capsules so easily without the fuss and mess of other e-cigs where you need to replace the fluid and coil, clean it out etc.
The only problem I have found so far is that I don't think the vapour you get from the e-cig is as 'dense' as some other e-cigs which I think makes it that little bit less satisfying. Having said that I've found it deals well with my cravings for cigarettes and I've cut down a lot already! The ease of changing the capsules far out ways any small downsides this e-cig has, great product!