I bought the nautilus tank with the hope that it would be all it was hyped to be. Man, was I disappointed with it. The first coil lasted about 2 weeks until the flavor died out. The other coil that came with it lasted 2 days and then it became expensive trying to find another one that worked. I think I gave up on this tank and it will collect dust for all I care; it became an expensive learning experience.
On the other hand, I bought a aerotank mega and was floored. It had better taste and vapor production off the bat. Plus, the coil from that one lasted a month. I am using the other one that came with it now for the second week and it is still going strong. I bought a 5 pack of replacement coils (much cheaper than the nautilus coils btw) when I bought the tank and have yet to use any. This has been over a month and a half. This has by far been my best vape with any factory type tank to date. For these reasons I would recommend the aerotank mega as it is much cheaper to maintain (coil wise) and much more of a reliable tank.
I'm vaping my Kanger Aeortank Mega as I type. Since the Nautilus coils went South I have changed back to the Mega. Even on the Mega, both the dual and single (T3S) coils are junk. I'm changing two in a 24 hour period as they rise from 1.8 ohms to 3 and sometimes 4 ohms before they quit vaping and read OP on my Provari. I start out at 3.4v and migrate to 3.7v and 4v before they fail completely.
The up side is that I keep dead coils in a zip lock and recoil them as needed. The vape is fine on a re-coil and they last for a long time. I envy anyone who hasn't encountered to bad coil heads. I can't seem to find any good ones.
*** If you order the air flow adapter for your Protank, keep the old base to use when recoiling. If you have one of the digital ohmmeters with the 510 socket, the air flow adapter allows you to use that to check resistance after re-coiling the head. Just screw it into the old base and install that onto the digital resistance checker. It's much easier than trying to use meter leads on an atomizer head.