I have the gripper, and it is a good device. Cheap? Yes. It has performed well so far. My only gripe is that you have to set the voltage lower than you would on say a Provari (I have one of those too) For example, at this moment I have a tank with a 3 ohm carto in it, on my Provari I run it at 5.5 volts, on the gripper I have to run it at 4 volts, anything higher, and the juice burns. Both devices use pulse width modulation, the Provari just does it better. In my opinion, the gripper is a fine backup for my Provari, but I wouldn't use it as my go to device.
My wife uses the gripper as her main PV and she loves it. I have dropped mine from about 3 feet onto our kitchen floor, and the only thing that happened was the battery popped out. As for batteries my wife as AW IMRs and I am using Efest IMRs and they both perform as expected, she gets a full day plus on one battery. Since I use mine as a secondary I get two to three full days. Overall, I like it, if I were to break it I would probably buy another, based on the cost. Better than having an Ego twist as a backup (Also have a couple of those)