I had Zamplebox. It was meh. Not their fault, just for me, and the way I vape, it's a flawed system. I'm picky, so I like a small percentage of what I try. I tend to either really like a flavor, or totally dislike it. Not much in between. And, I'm not one of those folks that can vape stuff I dislike just to get ride of it. If I don't like it, it goes in the cabinet of forgotten juices. They send small bottles, so if I did find something I liked, I vaped it in a day. And for every 10 I tried, I might like one. So, for me, it wasn't worth it. I'm far better off trying flavors in the local shops and just buying stuff I know I like.
That said, if you're new to vaping and want to experiment with various flavors to find what you like, it's a fine way to go. Or, if you're less picky than me and have a wider range of flavors you enjoy. I wouldn't go so far as to say the system is without merit, it's just not right for everyone.