I built a couple of CE2 tanks (one for regular and one for XL) that'll also hold a Vortex with a bit of tinkering (haven't done it yet)...but I find I'd rather just fill several cartos with different flavors and swap them out throughout the day. Not only does it keep the PV smaller and neater looking...I also know I have a spare ready to go in the event a coil decides to go. Just as a point of reference I now have something like 8 CE2, 2 Vortex, and one generic polyfill carto in rotation. I just pick a few each morning and drop them in an empty Altoid tin and I'm good for the day
Now with Vortex, it's so bloody easy to refill the things, and they flush for a new flavor very easily. For the short term...knowing it's possible to rewrap them to create custom HV and LR variants with relative ease myself...Vortex looks better every day

It's also nice to know that if these catch a decent market share, they'll start to become avilabe in more resistance options and thread types