I used to use them when they first started out. That was before flavor profiles were added and your choice of nicotine levels was pretty limited. When I had to change my credit card..after the famous Target breach my card company issued new ones to everybody, I forgot to update my billing info and decided after I had missed a shipment to just let the service go instead of renewing since I was/am getting a heck of a juice collection going and just didn't want to stockpile any more.
I did get some pretty good stuff that I probably wouldn't have otherwise tried, one of which became my sisters favorite ADV and one that I do re-order. Mostly it was just OK though.
The price is good for what you get, and there are always coupons in the box if you want to re-order something. My main problem was they do send quite a bit, I had bottles I still hadn't opened and the next shipment was already coming. Part of what makes the service such a great deal was the main reason I gave it up. If you don't mind the mystery box idea, and you either vape a ton or plan on using Zamplebox as your primary provider I still think it's an awesome deal. If you are like me and order liquids from multiple vendors plus buy a few at your local B & M you will probably find it's just too much juice to go through.
If their new subscription allows shipments less often I might be willing to try it again. The customer service is great!