In answer to the OP :
As a Career Trucker, dripping is out of the question. Trying to drip into an atty of any kind while steering 78,000 lbs. at 75 MPH on the Interstate is totally unsafe. Also, as a Flat Bed Driver, there a re chains, tarps, straps, tie-downs, .... a lot more work than just closing the back doors and driving. I broke six eGo Twists and ten Kanger T3's in less than six months. Along the way I had purchased my first REO Mini, and it just kept going no matter how much punishment it took. Then one day, my REO Mini fell out of shirt pocket. While I was tarping a full load of lumber. That was loaded onto a spread axle flat bed trailer. 11 Feet down and onto a hardened chip-and-run surface that had been compressed by years of tractor trailer traffic. I climbed down, picked up my REO, wiped it off and kept vaping. That was nearly two years ago, and I still use REOS Mods.
The REOS is indestructible, period. I have two REO Grands for at work, two REO VV Grands for at home and a REO Woodvil for out and about. I've recently acquired two ProVari, a P2 through Trade and purchased the new P3. Both have Kayfun RDA tank style attachments. They are nice - for lying on the couch and watching television.
If you are interested in sub-ohming and vapor production, look at a Low Profile (LP) REOS Grand. Reos Mods offers several dual coil and single coil attachments for the LP Grand. Also, there is a REONaut who is remodeling popular RDA's into Bottom Feed RBA's. His work can be found at Catfish Atty Mods. I recently had one of my VV Grand planed down, and purchased a remodeled Veritas from Catfish Atty Mods. Works great in single coil.
There is more to the REOS than an on-board bottle. Try conversing with the people of 'REOVille' for more info.