I much preferred the original Smoktek Vivi Tank to the new R Tank. I have modded all of original Vivi tanks to a Genesis style SS vertical wick. It takes a little bit of mechanical skill. The new R tank has an O ring on the top cap instead of a screw in, and the o rings just seem to disintegrate with my juices although the tanks show no signs of cracking. The tops of the R tank pop off too easily causing a real mess. My original R tank o rings just broke down after only one tank of juice. The Drunk tank works really well and is an easy rebuild as is the Vivi Nova since your don't even need a screwdriver to do it. The Drunk tank has the coil sitting further away from your mouth giving a cooler vape. The advantage of both of these is that you can easily replace the head without tools should you pop a coil and rebuild them at your leisure. I really like the Eternity with the ego T tank for out and about. Again, it's easy to replace the coil although a small tweezers in your kit would be helpful. The Eternity's are reported to leak in dripping mode (does not happen if you tilt the unit and drip away from the center vent hole), but I have not had that problem when using the T tank. The Eternity is small and fits well on my ego twists, but again it's my out and about vape. I am building a spark welder to weld NR wire to my Kanthal to avoid having uncoiled resistance wire just hanging free. All of my coils fail at the lead portion to the connecting post. That portion gets really hot, but this is an advanced rebuild so I would recommend something simple like the Vivi Nova or the Drunker tank. They will both give you hours of vaping pleasure. There are so many reasonably priced and functional clones out there that I think it is ridiculous to spend so much money on an original Greek. One might argue that you pay for quality, but no matter which RBA you buy, count on the coil failing sooner or later. Keeping two of them around would break the bank, providing you could actually find two to purchase.