Quote Originally Posted by saeyedoc View Post
Love the stealth factor. We got into them when we went to Denver this summer. You can buy pre-loaded cartridges so it's very convenient. They still have some QC issues though, sometimes they just quit working. The ones that take wax,etc. work more consistently, but not as convenient.
Usually the battery is the culprit, most of the time underpowered. There are some good companies out there that have legit QC, it just takes some time to find them.