I just got my VAMO from a coop like it so far in full length or shorty. My button tops and flat tops work just fine however i've noticed the that spring isn't that firm and my flat top 18650 (even with a nipple top) shake around in the cylinder and shut the device off. My ViVi Nova (which I prefer) works great on the device in VV and VW. However, I noticed that while running a dual coil eGO carto at 3.7v (with the 18650) after 2 or so hits the device shuts off, however it doesn't happen when I'm running the device on an 18350 battery. Any ideas?
Other than that and the batteries shakin' around I like it...
You'll probably have to replace the spring with something stronger, or do as I have and put a lager spring around it. I had to replace the original spring after my incident with a battery shorting out. It's best to leave the original in place because if you just set one in it doesn't get a good enough connection. Just find a larger one that will fit over it and you should be good to go. I robbed one out of an old 2 AA cell flashlight and it works fine. Also this way you can take it out if you run 2 18350's and it wont put as much pressure against the + conductor which is attached to the circuit board.