I have had mine for 4 days now. I love it. I have Twists, VTube, and now this one. This one blows the others out of the water. It really is powerful. I found it light weight and it fits my hand nicely. I would prefer the firing button in a different spot, but it's really not a big deal. The battery door works well. It was a bit stiff at first, but now it's great. The only thing I don't like about the Gripper is that when you replace the battery you have to turn the machine back on and set the voltage again. If I changed my battery quickly enough on the VTube it would hold my last settings. Again, not really a big deal, 5 clicks and it is back on, just a minor complaint.
I would vape on my VTube at 4.6 to 5V. On the new Gripper, I vape at 4V down to 3.5V, same juice same Vivi Novas. Overall, I love it. My VTube just sits now.
I know it is strange, but I really missed the rubber coating that the Twists had. Since I couldn't find any other VV mods that had the rubber coating, trying the Gripper was a no brainer for me. It exceeded my expectations.