I ordered the mini sub tank from Momandpopsvaporshop saturday and it came today! Fast shipping! anyway, it has grommets just like the chibi, the difference is they add o-rings to the groves in the grommets and they also have a hole and screw in the tank for easy filling. I haven't tried it yet, I usually only keep one carto/tank going at a time so I'm waiting till the carto I am using now to peter out so I can change to a new one.. it's been going almost a week. As long as a carto performs to my satisfaction.. I use it!
The grommet type tanks, the chibi, does not slide around at all. I do keep mine in my purse and it hasn't leaked either. I wouldn't be too rough on it though.