By Ex-smoker from United Kingdom
The eroll mac is a great cigalike and I use it for going out and about, super convenient what with the charging case and all.
The cartridges are great in concept but not without their flaws. They burn out fairly quickly if you aren't careful. Mainly however the airflow is too small for my liking, making for a very resistant drag. I used to pull fairly hard when smoking cigarettes so these cartridges don't quite give me the throat hit I want (although that does depend on the juice i'm using as well).
Make sure to use high PG or you will trash them. Also I'd advise a few pulls without the battery attached even after priming just to make sure they are soaked.
Fairly expensive, especially given that you can sometimes get a dud. But I'm sticking with them.