The clear cartomizers have design issues. There are videos out there showing the inadequacies. They're very difficult to fill, the plastic cracks at the base, causing them to leak, they pop apart, spilling all your
juice...
They need a redesign. Leaford has said they're working on it, but I doubt you'll see them soon. Too many issues to overcome at the moment.
Although the one video I did see, the guy really liked the way they vaped, and said if it weren't for the problems, he'd be using them daily. So there's a bright future for these things, at some point.