I have the "little Gripper"...great device! You can buy a couple of batteries and a dual (or more) chamber charger and just carry a battery or two with you when you go out if you are worried about the battery dying on you (be SURE to use a battery box to carry batteries!) My little Gripper is one of my "go to" APVs for going out where vaping might not be well received if done openly. Really love mine!
I have the Vmod too...only I have the XL version and I LOVE IT!!!!! Probably one of the very BEST APVs I have!! And I have a LOT of PVs and APVs, I promise you! All kinds from regulated, unregulated, VV and mechanical. There is a learning curve to using it...but it doesn't take long. The flavor and TH is amazing. I like a "cooler" hit too...so I use the 2ohm super shorty cartomizers, or the 2.2 ohm Silos from Vapage. You can use atomizers, too. You cannot use a wick style clearomizer on them. My Vmod is my top favorite and first in rotation device now...and has been for a month (since I got it) now. The Vmod is mechanical...this means that there are no chips or wires to fry and break. It also means you have a very big range of resistances you can try using....and the XL version is "kickable" (for variable wattage).
I have the VV Gripper and find it an excellent VV device. The body construction isn't the most sturdy, however. But with a little care it will serve well for a good long time.
I also have the Ovale V8 and V6. Both models are terrific, and are built more sturdy than the VV Gripper. They do have a "short protection" so they will blink at you if you take long draws, but that is about the only drawback with them. The V6 will not read your ohms for you nor does it have a voltage meter...like the V8 does. But they are excellent box mods!